Qu’est-ce qu’une « lingua franca » ? Brève histoire, des croisades à nos jours

Source: The Conversation – in French – By Alexandra Aikhenvald, Professor and Australian Laureate Fellow, Jawun Research Institute, CQUniversity Australia

Face à l’expansion de l’anglais, la résilience des locuteurs et des cultures pourrait bien rebattre les cartes. Gokul Gurung/Unsplash, CC BY

Pourquoi certaines langues s’imposent-elles comme outils universels avant de décliner ? De l’Antiquité à l’ère numérique, les lingua francas suivent les routes du pouvoir et des échanges.


Lorsque les Croisés débarquent sur les rivages orientaux de la Méditerranée à la fin du XIe siècle, ils doivent communiquer entre eux, mais aussi avec les marchands et les populations locales.

Beaucoup parlent alors différentes langues romanes : l’italien (notamment celui des puissantes cités-États de Venise et de Gênes), le provençal, le français ou encore leur ancêtre commun, le latin.

La plupart des Occidentaux présents en Europe du Sud sont français, en particulier originaires de la zone comprise entre Marseille et Gênes, d’où partent navires et marchands vers le Moyen-Orient. Ces Occidentaux sont désignés collectivement par les Arabes et les Grecs sous le nom de « Francs ».

Autour de la quatrième croisade (1202–1204), voire un peu plus tôt, une langue composite émerge progressivement en Méditerranée orientale, avant de se diffuser vers l’ouest. Cette langue commune, utilisée par les « Francs » et par ceux qui commercent et combattent avec eux, est aussi appelée sabir, italien bâtard ou espagnol bâtard. Mais c’est sans doute sous le nom de lingua franca que vous la connaissez le mieux : littéralement, la « langue des Francs ».

Cette langue franque est un mélange d’italien, de français et d’espagnol simplifiés, enrichi de quelques apports arabes et turcs. Elle est utilisée sur les rivages méditerranéens du Moyen-Orient jusqu’à la fin du XIXe siècle, avant de tomber en désuétude.

Écrit en minuscules, lingua franca désigne aujourd’hui toute langue servant de moyen de communication entre des personnes qui n’en partagent pas d’autre.

Une tradition ancienne

Les lingua francas remontent à l’Antiquité. Le sanskrit a ainsi servi de langue véhiculaire dans une grande partie de l’Asie du Sud-Est et de l’Asie centrale au cours du premier millénaire de notre ère, notamment par le biais des échanges commerciaux et de la diffusion religieuse.

Autour de la Méditerranée, le grec joue ce rôle d’environ 300 avant J.-C. à 500 après J.-C. : il est utilisé dans le commerce, la littérature, l’enseignement et dans la propagation du christianisme primitif.

Entre le IIe et le IVe siècles, le latin standard supplante le grec comme lingua franca de l’Église catholique en expansion. Il s’impose alors comme langue paneuropéenne de la religion, de la culture et du savoir, et le demeure jusqu’au XIXe siècle.

Un pendentif en or portant une inscription en latin
Le latin devient la lingua franca européenne, comme l’illustre ce pendentif britannique du XIIe siècle.
The Metropolitan Museum of Art

À partir du XVIIe siècle, l’arabe s’impose comme une _lingua franc_a dans l’ensemble du monde islamique, reliant des communautés d’Afrique et d’Asie.

Au même siècle, avec l’essor de la France comme puissance économique, le français remplace progressivement le latin dans de nombreux domaines et devient la première lingua franca « mondiale » en politique, diplomatie, commerce et éducation. Langue des cours royales, il est utilisé par les savants, les aristocrates, les marchands et les diplomates pour communiquer et écrire entre eux. Le français demeure la principale langue des relations internationales jusqu’à la fin de la Seconde Guerre mondiale.

Après les années 1940, en partie sous l’effet de l’influence croissante des États-Unis, l’anglais s’impose comme la principale lingua franca à l’échelle mondiale.

Fabriquer une nouvelle langue

Avec l’expansion coloniale des puissances impériales et de leurs langues — espagnol, anglais, français, portugais, allemand et néerlandais — à partir du XVe siècle environ, le terme lingua franca en vient à être utilisé comme un nom commun.

Tout au long de la colonisation européenne, des personnes issues de groupes linguistiques différents sont contraintes de travailler ensemble comme esclaves ou engagés sous contrat. Elles communiquent entre elles, ainsi qu’avec leurs maîtres, au moyen d’une langue simplifiée, utilisée pour des besoins limités : des ordres simples, des questions, des énoncés basiques mêlant les éléments dont chacun dispose. Ce type de moyen de communication improvisé est appelé pidgin (qui viendrait du mot anglais « business »).

Les pidgins peuvent servir de lingua franca. Lorsque leurs locuteurs commencent à se marier entre eux, un pidgin peut devenir la seule langue parlée par la génération suivante. Il se développe alors en une langue à part entière — un créole — utilisée dans tous les contextes.

Des créoles comme le tok pisin en Papouasie-Nouvelle-Guinée, le sranan au Suriname, le kristang en Malaisie ou encore le créole haïtien en Haïti servent aujourd’hui de lingua franca dans ces pays.

Une langue globale peut aussi être créée de toutes pièces.

La fin du XIXe siècle voit fleurir les projets de langues universelles. La plus célèbre est l’espéranto, « langue de l’espoir », créé par Ludwik Zamenhof en 1887 comme « langue internationale », c’est-à-dire une lingua franca générale. L’espéranto compte encore aujourd’hui quelques milliers de locuteurs natifs et bien davantage d’adeptes, mais son usage tend progressivement à reculer.

La « lingua franca » mondiale aujourd’hui

Les lingua francas apparaissent lorsqu’elles deviennent nécessaires, puis déclinent lorsqu’elles sont remplacées par d’autres. L’allemand a ainsi cessé d’en être une avec la perte des colonies après la Première Guerre mondiale. Le portugais reste une lingua franca au Brésil, et l’espagnol dans d’autres pays d’Amérique du Sud.

Quant au français, son empreinte mondiale perdure : à l’étranger, on envoie encore une lettre par avion ou poste restante.

Mais il y a un grand gagnant, loin devant les autres. L’anglais est désormais devenu la langue mondiale, s’étendant bien au-delà des locuteurs natifs et des anciennes colonies des puissances anglophones. Il est la langue de la diplomatie internationale, du monde académique et, surtout, des avancées technologiques, des réseaux sociaux et de l’intelligence artificielle.

La diffusion rapide de l’anglais menace-t-elle de faire disparaître les autres langues, qu’il s’agisse de langues minoritaires ou d’autres lingua francas, et plus largement la diversité linguistique à l’échelle mondiale ? La question reste ouverte. L’importance croissante du mandarin comme principale lingua franca en Chine, de l’arabe à travers l’Afrique et le Moyen-Orient, ainsi que la résilience des locuteurs à faire vivre leurs langues – et, avec elles, leurs cultures et leurs histoires – pourraient bien contenir l’hégémonie de l’anglais.

The Conversation

Alexandra Aikhenvald ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Qu’est-ce qu’une « lingua franca » ? Brève histoire, des croisades à nos jours – https://theconversation.com/quest-ce-quune-lingua-franca-breve-histoire-des-croisades-a-nos-jours-281649

Dans les bas rapiécés de l’homme le plus riche des États-Unis, le travail oublié des femmes américaines

Source: The Conversation – in French – By Emily J. Whitted, Ph.D. Candidate in Early American History, UMass Amherst

Rapiécer, gérer, entretenir : dans le foyer de l’un des hommes les plus riches d’Amérique, des femmes ont contribué, sans reconnaissance, à une prospérité qui leur échappait.


À sa mort en 1831, Stephen Girard – marchand, banquier et philanthrope de Philadelphie – était l’homme le plus riche des États-Unis. Dans son testament, il légua à la ville de Philadelphie (Pennsylvanie, Nord-Est des États-Unis) un don exceptionnel d’environ 6 millions de dollars, soit près de 194 millions d’euros aujourd’hui.

Girard demanda notamment qu’une partie de cette somme soit utilisée pour fonder un internat destiné aux garçons blancs pauvres et orphelins. Aujourd’hui, cet établissement, qui accueille des élèves du primaire au lycée, est connu sous le nom de Girard College et admet des élèves issus de milieux défavorisés, sans distinction de race ni de genre. L’institution a hérité des biens matériels de Girard, parmi lesquels du mobilier, des papiers personnels et des vêtements – dont une paire de bas de soie abondamment rapiécés.

Leur conservation peut surprendre : pourquoi l’homme le plus riche des États-Unis portait-il des vêtements raccommodés ? En tant qu’historienne du textile, spécialisée dans le travail du raccommodage dans l’Amérique des débuts, j’ai étudié les points utilisés pour réparer les bas de Girard, ainsi que ses riches archives.

Croisées, ces sources historiques m’ont permis de mettre au jour de nouveaux éléments sur la valeur des textiles dans l’Amérique d’alors, mais aussi sur le rôle des femmes – notamment celles qui travaillaient dans la maison du riche marchand – dans l’essor économique du pays.

Ce que nous disent ces bas

Les textiles étaient utilisés au quotidien par la quasi-totalité des Américains de l’époque coloniale et des débuts de la République et constituaient alors bien souvent les biens les plus précieux que l’on pouvait posséder.

Malgré la mécanisation à grande échelle, ils coûtaient cher en raison du prix des matières premières et du travail qualifié nécessaire à la fabrication des étoffes ; ils étaient en outre fréquemment importés. À la fin du XVIIIe et au début du XIXe siècle, les États-Unis voyaient émerger une industrie textile nationale, mais de nombreux Américains continuaient d’importer des tissus depuis l’étranger, notamment de Grande-Bretagne, de France et d’Inde. Les factures du foyer de Girard montrent qu’il achetait régulièrement une grande partie de ses vêtements – y compris ses bas de soie – en France.

La forte valeur des textiles à cette époque explique que même les foyers les plus aisés jetaient rarement les vêtements abîmés. On les réparait plutôt, à l’aide d’aiguilles et de fil. Si certains hommes pratiquaient aussi le raccommodage, l’immense majorité de ces travaux était réalisée par des femmes.

Les raccommodeuses : Sally, Polly et Hannah

Au sein du foyer de Girard, au moins trois femmes se chargeaient de repriser ses bas de soie et ses autres vêtements.

Bien que Girard ait été marié, son épouse Mary fut internée pour troubles mentaux à l’hôpital de Pennsylvanie en 1790, et le couple n’eut pas d’enfants. En l’absence de Mary, Girard eut plusieurs maîtresses qui faisaient office de gouvernantes : Sally Bickham, une femme quaker que Girard décrit dans une lettre comme une « tayloress », c’est-à-dire couturière, et Polly Kenton, blanchisseuse. Dans le cadre de leur travail, elles géraient les affaires domestiques et les achats de Girard, assurant le bon fonctionnement de son quotidien.

Par ailleurs, une femme noire nommée Hannah Brown, originaire de Saint-Domingue, ancienne colonie française correspondant aujourd’hui à Haïti, fut réduite en esclavage au sein du foyer de Girard pendant plus de quarante ans. Et ce, alors même que la loi d’abolition progressive adoptée en Pennsylvanie en 1780 aurait dû lui garantir la liberté dans les six mois suivant son arrivée aux États-Unis. L’abolition progressive n’y fut appliquée que de manière inégale, permettant à des propriétaires d’esclaves comme Girard d’en contourner les effets. Le testament du marchand accorda finalement la liberté à Hannah Brown.

Toutes trois travaillaient au service de Girard : elles reprisaient ses bas, géraient les tâches quotidiennes du foyer et veillaient à l’entretien de la maison. Les trois techniques de raccommodage visibles sur ses bas – comme le reprisage à la suisse, le reprisage tissé ou encore le renforcement des talons – constituent autant de traces matérielles de leur travail, aux côtés des archives écrites telles que les factures domestiques, les lettres et les reçus.

Aux premiers temps des États-Unis, de nombreuses femmes, libres ou réduites en esclavage, accomplissaient un travail domestique non rémunéré. Pourtant, ce travail a été une force essentielle de la croissance économique nationale au début du XIXe siècle. Partout dans le pays, des hommes comme Girard ont encouragé et tiré profit de l’industrialisation et de l’expansion des activités commerciales ; mais c’est le travail domestique non rémunéré des femmes qui a rendu possibles leur participation et leurs profits.

Si les habitants de Philadelphie ne voient aujourd’hui leurs noms ni sur les grandes artères ni sur les bâtiments de la ville, les efforts conjugués de Sally, Polly et Hannah — dissimulés dans les chaussures de Girard et éclipsés par l’ampleur de son héritage historique à Philadelphie — ont été essentiels à sa réussite économique.

The Conversation

Emily J. Whitted a reçu des financements de The Library Company of Philadelphia.

ref. Dans les bas rapiécés de l’homme le plus riche des États-Unis, le travail oublié des femmes américaines – https://theconversation.com/dans-les-bas-rapieces-de-lhomme-le-plus-riche-des-etats-unis-le-travail-oublie-des-femmes-americaines-282019

L’abandon d’une stratégie vieille de 250 ans… Ce que change la fin de l’obligation vaccinale dans l’armée américaine

Source: The Conversation – France in French (3) – By Katrine L. Wallace, Assistant Professor of Epidemiology and Biostatistics, University of Illinois Chicago

L’armée opère généralement dans des conditions – caserne, navire, etc. – qui favorisent la propagation des virus respiratoires Bumble Dee/Shutterstock

De George Washington à la Seconde Guerre mondiale, la vaccination a été pensée comme un outil stratégique face aux maladies capables de décimer les troupes. Aujourd’hui, cette logique historique entre en tension avec la montée des revendications individuelles.


Pour la première fois depuis près de 80 ans, les militaires états-uniens ne seront plus tenus de recevoir le vaccin annuel contre la grippe. Le secrétaire à la Défense Pete Hegseth a annoncé ce changement le 22 avril 2026. Invoquant l’autonomie médicale et la liberté religieuse, il a qualifié cette obligation de « trop large et dénuée de rationalité », déclarant aux soldats que « votre corps, votre foi et vos convictions ne sont pas négociables ».

L’obligation vaccinale contre la grippe à laquelle Pete Hegseth a mis fin était en vigueur depuis 1945, avec une brève interruption en 1949. Elle s’inscrivait dans une tradition d’obligations vaccinales militaires presque aussi ancienne que les États-Unis eux-mêmes.

En tant qu’épidémiologiste spécialisée dans les maladies évitables par la vaccination, je trouve la fin de cette obligation moins marquante pour ses effets immédiats que pour ce qu’elle révèle. Pendant la majeure partie de l’histoire américaine, les commandants militaires partaient du principe que les maladies infectieuses pouvaient leur faire perdre une guerre, raison pour laquelle la vaccination relevait de la préparation opérationnelle plutôt que d’un choix individuel.

Une tradition qui remonte à George Washington

La première obligation vaccinale militaire américaine est antérieure à la Constitution. À l’hiver 1777, le général George Washington ordonne l’inoculation massive de l’armée continentale contre la variole.

Sa décision n’était pas idéologique – elle était stratégique. L’année précédente, une épidémie de variole avait ravagé les troupes américaines près de Québec, contribuant à l’effondrement de la campagne du Nord. John Adams écrivit à sa femme Abigail que la variole tuait dix soldats pour un seul tombé au combat.

L’inoculation en 1777 comportait elle-même des risques. La procédure, appelée variolisation, consistait à infecter volontairement un soldat avec une faible dose du virus de la variole afin de provoquer une immunité. George Washington a fait le pari qu’il valait mieux perdre quelques hommes à cause de l’inoculation que perdre une guerre face au virus. Des historiens ont attribué à cette décision le salut de l’armée continentale.

La pandémie de Covid-19 a reconfiguré les enjeux politiques autour des obligations vaccinales.

Ce schéma s’est maintenu pendant des siècles : lorsqu’une maladie infectieuse risquait de mettre plus de soldats hors de combat que les tirs ennemis, l’armée imposait des mesures de protection.

Les troupes américaines ont été vaccinées contre la variole de la guerre de 1812 jusqu’à la Seconde Guerre mondiale. Pendant la Première Guerre mondiale, l’armée a ajouté la vaccination contre la typhoïde. Lors de la Seconde Guerre mondiale, elle a élargi les obligations vaccinales pour inclure également le tétanos, le choléra, la diphtérie, la peste, la fièvre jaune et, en 1945, la grippe.

1945 : nouvelle guerre, nouveau vaccin

L’obligation vaccinale contre la grippe trouve son origine dans les expériences militaires lors de la pandémie de grippe de 1918. Ce printemps-là, une nouvelle souche de grippe s’est propagée dans des camps d’entraînement militaires surpeuplés avant de gagner l’Europe avec les troupes américaines. Environ 45 000 soldats américains sont morts de la grippe pendant la Première Guerre mondiale, presque autant que les quelque 53 000 tués au combat.

La pandémie de 1918 a fait la démonstration qu’un virus respiratoire pouvait paralyser une armée. Aussi, en 1941, alors que le pays se préparait à entrer dans un nouveau conflit mondial, l’armée américaine a-t-elle mis en place une commission sur la grippe qui s’est associée à l’université du Michigan pour développer le premier vaccin contre cette infection. Des essais cliniques menés sur des recrues ont montré qu’il réduisait de 85 % l’incidence de la maladie, et en 1945, l’armée a rendu la vaccination obligatoire. Environ 7 millions de militaires ont été vaccinés cette année-là.

L’obligation a été brièvement suspendue en 1949, lorsque les scientifiques ont compris que le vaccin devait être régulièrement mis à jour en raison de l’évolution du virus. Une fois les formulations adaptées de manière saisonnière, l’obligation a été rétablie au début des années 1950 et est restée en vigueur sans interruption jusqu’au changement de politique décidé par Pete Hegseth.

Hôpital d’urgence au camp Funston, au Kansas, en 1918, pendant l’épidémie de grippe
La pandémie de grippe de 1918 a tué presque autant de soldats américains que les combats pendant la Première Guerre mondiale.
Otis Historical Archives, National Museum of Health and Medicine

Le Covid-19 a transformé la politique vaccinale

Pendant des décennies, les obligations vaccinales faisaient partie intégrante et peu contestée de la vie militaire. La pandémie de Covid-19 a changé la donne.

En août 2021, tous les militaires ont été sommés de se faire vacciner contre le Covid-19. Plus de 98 % des soldats en service actif ont obtempéré, mais cette obligation est devenue un point de crispation. Plus de 8 000 militaires ont été renvoyés de force pour avoir refusé le vaccin.

En 2023, le Congrès a adopté une loi obligeant Le Pentagone à annuler l’obligation vaccinale contre le Covid-19. Ce revirement a reconfiguré les enjeux politiques autour des obligations vaccinales dans l’armée. En janvier 2025, le président Donald Trump a ordonné la réintégration, avec indemnités rétroactives, des militaires renvoyés dans ce cadre.

En annonçant la fin de l’obligation vaccinale contre la grippe, Pete Hegseth s’est largement appuyé sur le vocabulaire de la « liberté médicale », issu des débats autour des vaccins contre le Covid-19, plutôt que sur de nouvelles données concernant la grippe ou l’efficacité du vaccin. Le mouvement pour la liberté médicale s’oppose à l’intervention de l’État dans ce que ses partisans considèrent comme des décisions de santé personnelles, y compris des recommandations de santé publique telles que les obligations vaccinales, le port du masque ou la distanciation sociale.

La justification vaccinale tient-elle toujours ?

Les critiques de l’obligation vaccinale contre la grippe dans l’armée avancent que la grippe constitue aujourd’hui une menace plus modérée qu’en 1918, que les militaires sont en meilleure santé que la population générale et que, pour un virus saisonnier, le choix individuel devrait primer sur la logique de santé publique.

L’épidémiologie raconte une autre histoire.

Même si l’intensité des saisons grippales varie, le virus mute de manière si imprévisible que des pandémies comme celles de 1918, 1957, 1968 et 2009 restent une possibilité récurrente. La grippe continue d’ailleurs de causer chaque année des hospitalisations et des décès par dizaines de milliers aux États-Unis. Les Centers for Disease Control and Prevention estiment que le vaccin contre la grippe a ainsi évité environ 180 000 hospitalisations et 12 000 décès lors de la saison 2024-2025.

L’armée opère précisément dans des conditions qui favorisent la propagation des virus respiratoires : centres d’entraînement, casernes, navires ou sous-marins où les individus vivent en promiscuité.

La logique qui a conduit George Washington en 1777 et le Surgeon General de l’armée en 1945 à imposer la vaccination n’a, au fond, guère changé. Un soldat malade ne peut ni être déployé, ni s’entraîner, et peut transmettre la maladie à toute une unité.

Ce qui a changé, en revanche, c’est le poids politique accordé au refus individuel et c’est cela, bien plus que la question de l’efficacité du vaccin, que reflète la fin de cette obligation

The Conversation

Katrine L. Wallace ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. L’abandon d’une stratégie vieille de 250 ans… Ce que change la fin de l’obligation vaccinale dans l’armée américaine – https://theconversation.com/labandon-dune-strategie-vieille-de-250-ans-ce-que-change-la-fin-de-lobligation-vaccinale-dans-larmee-americaine-281795

Les résidus de cocaïne dans les rivières et les océans modifient les déplacements des saumons

Source: The Conversation – in French – By Marcus Michelangeli, Lecturer, Environmental Sustainability and Management, Griffith University

Les poissons exposés à la benzoylecgonine parcouraient jusqu’à 1,9 fois plus de distance par semaine. Hans-Petter Fjeld / Wikimedia, CC BY

La présence croissante de drogues dans les milieux aquatiques n’est plus anecdotique. Une nouvelle étude menée en Suède montre que même à faibles doses, ces substances peuvent perturber les déplacements de poissons et potentiellement fragiliser des espèces déjà sous pression.


Du poisson ou des requins sous cocaïne : l’image semble tout droit sortie d’un scénario hollywoodien, mais la réalité est bien moins divertissante. De plus en plus souvent, les scientifiques détectent de la cocaïne et d’autres drogues puissantes dans les milieux aquatiques et les retrouvent jusque dans le cerveau et le corps des animaux sauvages.

Une étude de 2024 menée au Brésil a fait les gros titres après avoir mis en évidence la présence de cocaïne dans les muscles et le foie de requins sauvages capturés au large de Rio de Janeiro. Si cela peut surprendre, cette découverte reflète un phénomène plus large et en expansion : les drogues consommées par les humains se retrouvent désormais dans les rivières, les lacs et les océans du monde entier.

Dans notre nouvelle étude, publiée récemment dans Current Biology, nous avons cherché à comprendre ce que cela implique pour la faune sauvage.

Des poissons « sous cocaïne » dans la nature

Nous avons étudié comment des concentrations de cocaïne comparables à celles observées dans l’environnement influencent le comportement des poissons à l’état sauvage. Nous nous sommes également intéressés à une substance appelée benzoylecgonine, principal composé résiduel issu de la dégradation de la cocaïne par l’organisme.

Pour cela, nous avons mené une expérience dans le lac Vättern, en Suède, le deuxième plus grand lac du pays, où nous avons suivi de jeunes saumons atlantiques pendant huit semaines.

À l’aide d’implants chimiques à libération lente, nous avons exposé les poissons soit à la cocaïne, soit à la benzoylecgonine, puis suivi leurs déplacements grâce à la télémétrie acoustique. Cette méthode nous a permis d’observer leur comportement en milieu naturel, plutôt que dans des bassins de laboratoire.

Ce que nous avons observé est frappant. Les poissons exposés à la benzoylecgonine parcouraient jusqu’à 1,9 fois plus de distance par semaine que les poissons non exposés et se dispersaient jusqu’à 12,3 kilomètres plus loin à travers le lac. Les poissons exposés à la cocaïne présentaient une tendance similaire, mais l’effet était plus faible et moins constant.

Des eaux usées aux milieux aquatiques

Comment ces substances se retrouvent-elles dans les environnements aquatiques ?

Après consommation, la cocaïne est rapidement dégradée par l’organisme, principalement en benzoylecgonine. Des composés de ce type – résidus issus de la transformation d’une substance par le corps – sont appelés des métabolites. La drogue initiale comme son métabolite sont ensuite excrétés et rejoignent les systèmes d’eaux usées.

Or, les stations d’épuration ne sont pas conçues pour éliminer complètement ces composés : ils traversent donc les traitements et sont rejetés dans les rivières, les lacs et les eaux côtières.

Ce phénomène n’a rien de localisé. La cocaïne est désormais l’une des drogues illicites les plus fréquemment détectées dans les milieux aquatiques à l’échelle mondiale.

Une analyse globale a mis en évidence des concentrations moyennes dans les eaux de surface d’environ 105 nanogrammes par litre pour la cocaïne et 257 nanogrammes par litre pour la benzoylecgonine, avec des pics atteignant plusieurs milliers de nanogrammes. Si ces niveaux restent faibles, ils suscitent néanmoins des inquiétudes, car ces composés ciblent des systèmes cérébraux partagés par de nombreux animaux : même à faibles doses, ils peuvent donc potentiellement affecter la faune sauvage.

Pourquoi le comportement est crucial

Les changements de comportement comptent parmi les indicateurs les plus précoces et les plus sensibles d’une perturbation environnementale affectant la faune. Ils peuvent influencer des fonctions essentielles, depuis la recherche de nourriture et l’évitement des prédateurs jusqu’aux interactions sociales, à la reproduction et à la survie.

Lorsque des contaminants modifient les comportements, leurs effets peuvent se répercuter bien au-delà de l’individu. De légers changements dans la manière dont les animaux se déplacent, s’alimentent ou réagissent aux menaces peuvent, à plus grande échelle, affecter la dynamique des populations, les interactions entre espèces et le fonctionnement des écosystèmes dans leur ensemble.

Les changements que nous avons observés dans la manière dont les poissons se déplacent dans leur environnement après une exposition à la cocaïne pourraient entraîner une dépense énergétique accrue, une fréquentation d’habitats de moindre qualité ou encore une exposition plus importante au risque de prédation.

Pour des espèces comme le saumon atlantique, déjà soumises aux pressions du changement climatique, de la perte d’habitat et d’autres polluants, même de légères perturbations comportementales peuvent venir aggraver les difficultés auxquelles elles sont confrontées.

Pourquoi le métabolite compte

L’un des résultats les plus surprenants de notre étude est que la benzoylecgonine a eu un effet plus marqué sur le comportement des poissons que la cocaïne elle-même. C’est un point crucial, car les évaluations des risques environnementaux se concentrent généralement sur les substances consommées par les humains, comme la cocaïne, plutôt que sur celles qu’ils rejettent ensuite, comme la benzoylecgonine.

Or ces métabolites sont souvent plus abondants et plus persistants dans les milieux aquatiques. Nos résultats suggèrent que nous sous-estimons peut-être les risques écologiques liés à ces polluants.

Notre étude s’est concentrée sur le comportement, et non sur les effets à long terme sur la santé. Nous n’avons pas encore évalué si ces changements influencent la survie ou la reproduction.

Cependant, des travaux antérieurs montrent que la cocaïne et des composés apparentés peuvent modifier la chimie du cerveau, accroître le stress oxydant et perturber le métabolisme énergétique chez les animaux aquatiques. Ces processus étant étroitement liés à la santé et à la condition physique, ils laissent entrevoir des effets plus larges.

L’idée de « poissons sous cocaïne » peut faire sourire, mais elle renvoie à un problème bien plus vaste. Les milieux aquatiques sont de plus en plus contaminés par des mélanges complexes de substances d’origine humaine, des médicaments aux drogues illicites. Beaucoup de ces composés sont biologiquement actifs à de très faibles concentrations, et nous commençons à peine à en comprendre les effets.

The Conversation

Marcus Michelangeli travaille pour Griffith University. Il a reçu un financement et un soutien à la recherche du Conseil suédois de la recherche Formas (2022-00503), ainsi que du programme de recherche et d’innovation Horizon 2020 de l’Union européenne dans le cadre d’une bourse Marie Skłodowska-Curie (101061889) pour mener ces travaux.

Jack Brand travaille pour l’Université suédoise des sciences agricoles et reçoit un financement du Conseil suédois de la recherche Formas (2024-00507). Il occupe également un poste de chercheur invité à l’Institute of Zoology de la Zoological Society of London.

ref. Les résidus de cocaïne dans les rivières et les océans modifient les déplacements des saumons – https://theconversation.com/les-residus-de-coca-ne-dans-les-rivieres-et-les-oceans-modifient-les-deplacements-des-saumons-281545

Why postal codes shouldn’t determine RSV protection in Canada

Source: The Conversation – Canada – By Sophie Webb, Postdoctoral Fellow,  Bridge Research Consortium, Simon Fraser University

Respiratory syncytial virus (RSV) is a familiar seasonal illness, but the tools to prevent it are new. Canada has recently approved vaccines for older adults and pregnant people, along with a long-acting monoclonal antibody that can protect infants through their first RSV season.

These innovations offer new ways to reduce hospitalizations and severe illness. Yet whether Canadians can access them still depends largely on where they live.

Across the country, provincial RSV programs vary widely in eligibility, scope and public funding — see, for example, Ontario RSV program updates and Alberta immunization program information.




Read more:
RSV FAQ: What is RSV? Who is at risk? When should I seek emergency care for my child?


An infant eligible for publicly funded protection in one province may not be eligible in another. Seniors with similar health risks may face different access depending on their province. These differences are often dismissed as routine features of federalism.

But with World Immunization Week upon us, RSV provides the opportunity to ask a broader question: who’s responsible for delivering equitable access to vaccines in Canada?


Immunity and Society is a new series from The Conversation Canada that presents new vaccine discoveries and immune-based innovations that are changing how we understand and protect human health. Through a partnership with the Bridge Research Consortium, these articles — written by experts in Canada at the forefront of immunology, biomanufacturing, social science and humanities — explore the latest developments and their impacts.


New tools, uneven access

RSV prevention now includes vaccines for older adults and pregnant people, and a monoclonal antibody (nirsevimab) that offers season-long protection for infants with a single dose.

National guidance exists. The National Advisory Committee on Immunization recommends universal infant RSV immunization, but allows provinces to phase this in based on supply and cost. But these recommendations are advisory. Provinces ultimately decide what is publicly funded and for whom.

The result is a patchwork. Some provinces have expanded infant coverage, while others have limited access to those considered high risk. Adult and maternal programs also vary in eligibility, delivery and funding.

Cost plays a key role in these decisions. RSV therapies are expensive, and provinces must weigh them against competing health priorities. Epidemiological differences also matter, as do variations in disease burden and the additional challenges of vaccination in northern and remote communities.

Not all variation is inherently problematic. But together, these factors mean that access to protection is shaped as much by provincial priorities as by medical need.

When equity’s a goal but not a guarantee

In immunization policy, equity generally means ensuring that those at higher risk, or facing barriers to access, are protected first, and financial or geographic differences don’t determine who receives care.

RSV programs often emphasize protecting those at highest clinical risk, such as very young infants and people with underlying conditions. This approach is understandable. But it also narrows how equity operates in practice.

In a system where provinces determine their own budgets and priorities, equity can become something negotiated rather than guaranteed. One province may fund broader access; another may limit eligibility based on cost-effectiveness or capacity. The same intervention is therefore available to some populations and not others.

This shifts responsibility downward. Families must determine eligibility, navigate different rules, and sometimes absorb costs or logistical barriers to access. Equity becomes something people experience unevenly, rather than a guarantee built into the system.

COVID-19 offers a cautionary example. Communities identified as highest risk were often vaccinated later than wealthier neighbourhoods during early rollout phases. This prompted provinces to introduce reactive “hotspot” strategies that in some cases replicated the same effect. Simply naming groups as “equity-deserving” did not ensure timely access.

People in masks are vaccinated by health-care workers in protective gear inside a tent
A pop-up vaccine clinic in a Toronto hotspot neighbourhood in April 2021.
THE CANADIAN PRESS/Cole Burston

Governance and accountability

Canada’s immunization system involves multiple entities. Federal bodies approve products and issue recommendations. Provinces decide what to fund. Public health systems implement programs within local constraints.

While each level plays an essential role, none is clearly responsible for national equity, creating a governance gap.

Equity is widely endorsed, but no single body is accountable for delivering it nationally. RSV demonstrates how this plays out in practice — variation in immunization is accepted as a feature of federalism, rather than treated as a policy problem to be addressed.

Procurement adds another layer. Vaccine pricing and contract terms are not routinely disclosed in Canada, and negotiations with manufacturers are often confidential.

During COVID-19, federal vaccine contracts were released only after parliamentary pressure, with key details heavily redacted. Limited transparency makes it difficult to assess whether differences in access reflect pricing, negotiation leverage or policy choices.




Read more:
Consulting firms are the ‘shadow public service’ managing the response to COVID-19


Why it matters

RSV is one of the first major post-pandemic tests of Canada’s immunization system. It’s unlikely to be the last. New vaccines and antibody-based therapies are increasingly tailored to specific populations, making decisions about access more complex.

As these technologies evolve, governance matters more, not less. Without clearer accountability, innovations risk reinforcing variation rather than reducing it.




Read more:
Flu, RSV and COVID-19: Advice from family doctors on how to get through this winter’s ‘tripledemic’


RSV highlights a broader challenge in Canadian immunization policy — equity is widely invoked, but responsibility for delivering it remains diffuse. Without clearer co-ordination, transparency and shared expectations, access to protection will continue to depend on where people live.

For families of infants and seniors, that distinction is not abstract. It determines whether immunity is treated as a public good, or as a matter of postal code.

The Conversation

Cora Constantinescu receives funding from bioMerieux, GSK, merck, Pfizer, Sanofi, with funds being transferred to her University organisation

Sophie Webb does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Why postal codes shouldn’t determine RSV protection in Canada – https://theconversation.com/why-postal-codes-shouldnt-determine-rsv-protection-in-canada-278717

UK terror threat is raised – counter-terror expert explains how official prevention strategies work

Source: The Conversation – UK – By Elisa Orofino, Academic Lead for Extremism and Counter-Terrorism, Anglia Ruskin University

William Barton/Shutterstock

The UK has raised its terror threat level from “substantial” to “severe”, meaning an attack within the next six months is considered highly likely. The change means the threat level is at severe for the first time in four years. It came with a warning from the Home Office of an increased threat from individuals and small groups based in the UK.

Counter-terrorism in the UK centres on a strategy known as Contest – a key part of this is the Prevent programme. The primary objective of Prevent, as the name suggests, is to stop people becoming involved in terrorism or from supporting extremist ideologies.

As such, it is designed to deliver tailored early-intervention aimed at addressing risks of radicalisation, extremism and terrorism.

In my experience as a researcher in counter-terrorism studies, I have engaged extensively with Prevent practitioners. I have gained an insight into their work, which is carried out with commitment and dedication despite constraints in funding and resources.

A Prevent referral does not imply that someone has committed, or is suspected of committing, a criminal offence. Rather, it indicates that a professional with a statutory “Prevent duty” has raised concerns about someone’s behaviour, expressions or vulnerabilities. These professionals include teachers, healthcare workers and or social workers.

Recent data illustrates the scale of the programme: between April 2024 and March 2025, 8,778 people were referred to Prevent. This is the highest figure recorded since data collection began in 2015.

Notably, a significant proportion of these referrals involve young people, with 36% (3,192 cases) concerning children aged 11 to 15. A further 1,178 cases involved those aged 16 and 17.

rear view of young person in hoodie facing a chickenwire fence
More than a third of referrals to Prevent involved children.
Aoy_Charin/Shutterstock

The criteria for referral are broad, and they can include observable changes in behaviour, expressing extremist views, or signs of vulnerability that could make someone more susceptible to being radicalised.

Referrals are assessed by a panel that often include representatives from education, social services and law enforcement. In many cases, referrals do not progress beyond this initial stage. Instead, they may be signposted to other teams, such as social services, for more support.

But where there are still concerns, individuals may be offered support through the Channel programme. This is Prevent’s primary de-radicalisation mechanism. Channel is voluntary and confidential, and referrals can come from anyone and from any context. They are often issued by the police and education sector.

The support is tailored to the specific needs in each case and may include mentoring and mental health support. Participation is voluntary, and individuals can refuse to be involved or stop participating at any point.

Stigma and polarisation

Prevent is designed to be pre-emptive – intervening before criminal activity occurs. However, this breadth is also a source of ongoing controversy.

Critics argue that it can result in referrals based on ambiguous or misinterpreted behaviour. As such it has the potential to reinforce polarisation, particularly in relation to specific groups such as Muslims. This can clearly leave people feeling stigmatised, under surveillance or unfairly judged, particularly if they believe the referral was based on cultural, religious or political misunderstandings.

The scheme also has significant structural limitations as it functions as a time-limited intervention rather than a system of ongoing monitoring. Once a case is closed, the person is not subject to continuous oversight. This means that a previous referral does not eliminate the possibility of future risk – it simply means that the threshold for intervention was not met at that time.

It is important to remember that positive stories rarely get widespread attention. Every year, thousands of people in the UK receive early support and successfully disengage from radical and extremist ideologies.

Prevent operates in a difficult space between safeguarding and security, where risk is assessed before an offence occurs. While high-profile cases can amplify perceptions of failure, they do not reflect the full picture. Most referrals do not lead to further action, and many result in early, voluntary support that helps people disengage from harmful pathways.

At the same time, concerns around ambiguity and stigma remain valid. In short, rather than seeing Prevent as a measure of guilt, it’s important to recognise its limitations and its role as an early intervention tool.

The Conversation

Elisa Orofino does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. UK terror threat is raised – counter-terror expert explains how official prevention strategies work – https://theconversation.com/uk-terror-threat-is-raised-counter-terror-expert-explains-how-official-prevention-strategies-work-281996

The king’s state visit was a success – but there is still a chasm to bridge between UK and US outlooks

Source: The Conversation – UK – By Sam Edwards, Reader in Modern Political History, Loughborough University

As King Charles concludes his transatlantic travels with a visit to Bermuda, a British Overseas Territory, he can take pride in a job well done. His four-day state visit to the US – which concluded with a wreath-laying at Arlington National Cemetery and a block party in Virginia – appears to have been a success.

Amid a period of heightened tension between President Donald Trump and Prime Minister Keir Starmer, the king’s carefully calibrated speech to a joint session of Congress has secured praise on both sides of the Atlantic (and on both sides of the Congressional aisle).

It was a remarkable performance: careful, diplomatic, occasionally pointed and at times both charming and witty. Perhaps we should not be that surprised. The king is a highly experienced diplomat, and while this was his first address to Congress, it was his 20th visit to Washington – as he himself noted.




Read more:
How King Charles charmed the US while taking digs at Trump


But what does the undoubtedly warm American response to the king’s visit mean for the future of the US-UK “special relationship”?

On its own, no act of royal diplomacy, however well executed, can deliver an instant reset in US-UK relations. Nor can it force an American president of any stripe – let alone the current incumbent – to change tack or alter approach.

On this, history offers a salutary lesson. For all the positive impact of King George VI’s June 1939 visit to the US, when war broke out just a few months later, it did not lead to instant American intervention.

The queen’s visit in 1957 was similarly well received. But the work of rebuilding transatlantic trust – so damaged by the Suez crisis – remained ongoing in the months that followed.

This latest state visit will similarly offer no quick fix. But like its predecessors, it might shift the dial on the current US-UK dialogue – and perhaps help to temper the tone, at least for a while.

For the UK, there has already been one immediate win: Trump has decided to remove whisky tariffs in honour of the king’s visit. This will be very much welcomed by the Scottish whisky industry.

The potential long-term impact of the king’s visit is harder to ascertain. Not least because this will be determined by variables well beyond either his or Starmer’s control: contemporary geopolitics, especially as affected by the wars in Iran and Ukraine. Despite this week’s mutual exchange of praise and platitudes, the distance between London and Washington on these matters remains substantive.

Worlds apart

There was a brief glimpse of these differences in two of the speeches: the king’s to Congress and, on the same day, the president’s at the White House.

The king’s speech lingered on the shared ties of history and, especially, on democratic values and ideals. It included references to the importance of compassion and interfaith dialogue, and celebrated the strength of what the king called “our vibrant, diverse and free societies”.

President Trump’s speech at the White House a few hours earlier similarly featured references to the transatlantic connections born of history. But elsewhere, his tone and intent seemed rather different.

Trump celebrated “the blood and noble spirit of the British” – qualities which had provided American revolutionaries with a “majestic inheritance”. At one point, he even declared that the patriots of the American Revolution had been animated by the “Anglo-Saxon courage” in their veins. This is a claim on American history that one commentator has suggested “walks up to the edge of white nationalism”.

There are indeed echoes here of an early 20th-century diplomatic discourse known as Anglo-Saxonism. Once popular and pervasive among transatlantic writers and diplomats (including those of a nativist bent), it largely fell out of favour in the years between the world wars – its racial assumptions increasingly untenable.

As long ago as December 1918, President Woodrow Wilson explicitly told an audience of British dignitaries – including King Charles’s great-grandfather, George V – that they must not “think of us as Anglo-Saxons, for that term can no longer be rightly applied to the people of the United States”.

Wilson was the first serving US president to visit Britain, and, like Trump, had a British mother (Trump’s was from Tong on the Isle of Lewis, Scotland). Wil point – made in advance of the Paris Peace Conference – was that the US was a melting pot, not a monoculture.

King Charles’s speech hailed the importance of alliances (Nato), of multilateral institutions (the UN), and of the rule of law. These, he argued, are what has delivered eight decades of transatlantic peace and prosperity.

From the president, meanwhile, came a celebration of Anglo-American blood brotherhood. It was at times reminiscent of thinking (and language) which his predecessor Wilson – no “woke” radical – had called into question well over a century ago.

These two visions of the US-UK relationship, distinct in their underlying assumptions, reflect a broader geopolitical shift – one which has increasingly strained the transatlantic relationship in recent months.

The king’s vision, indicative of widespread sentiment in Europe, represents an affirmation of the post-1945 world order. The other, with its echoes of the early 20th century, is disruptive. Between them lies a chasm of significant proportions, and bridging it will be the task of today’s transatlantic diplomats.

The Conversation

Sam Edwards has previously received funding from the ESRC and the US-UK Fulbright Commission. Sam is a Governor of The American Library (Norwich) and a Trustee of Sulgrave Manor (Northamptonshire).

ref. The king’s state visit was a success – but there is still a chasm to bridge between UK and US outlooks – https://theconversation.com/the-kings-state-visit-was-a-success-but-there-is-still-a-chasm-to-bridge-between-uk-and-us-outlooks-281948

Why the 60-day War Powers Resolution deadline doesn’t actually constrain presidents

Source: The Conversation – USA – By Jasmine Farrier, Professor of Political Science, University of Louisville

A TV displays U.S. President Donald Trump’s prime-time address on the war in Iran inside a Cheesecake Factory on April 1, 2026, in Washington, D.C. Anna Moneymaker/Getty Images

May 1, 2026, marks the 60th day of Operation Epic Fury in Iran – a symbolically significant date designating when a president who has mounted unilateral military operations must receive Congressional approval or wind it down.

However, the complex history of the War Powers Resolution clock demonstrates it is a toothless milestone.

The Trump administration signaled on April 30, 2026, that it would ignore that deadline, set by the War Powers Resolution. Secretary of Defense Pete Hegseth testified before the Senate Armed Services Committee that “we are in a cease-fire right now, which my understanding is that the 60-day clock pauses or stops in a cease-fire. That’s our understanding, so you know.”

Sen. Tim Kaine of Virginia, a Democrat, responded that the 60-day threshold poses a “legal question” and “constitutional concerns.”

This is not the first time presidents and members of Congress have sparred on the meaning of the War Powers Resolution. What happens next will play out through regular politics, because the conflict is not a matter of simple legal interpretation.

War: Collective judgment

In the U.S. Constitution, Congress and the president share war powers.

In the shadow of political struggles in the final years of the Vietnam War, Congress passed the War Powers Resolution in 1973 to “insure that the collective judgment of both the Congress and the President will apply to the introduction of United States Armed Forces into hostilities.”

A crucial section of the resolution reasserts legislators’ role, and makes clear that the constitutional power of the president to make war is subject to, or exercised with, the following conditions: a Congressional declaration of war; specific statutory authorization; or a national emergency created by attack upon the United States, its territories or possessions or its armed forces.

For new military campaigns that do not meet these criteria, the resolution included a 60-day clock that begins when a president reports the action to congressional leadership within 48 hours of the action beginning.

The clock can be expanded to up to 90 days upon presidential determination and certification of “unavoidable military necessity respecting the safety of United States Armed Forces” related to removal of troops.

After 60 to 90 days, the resolution originally said this type of unilateral military action would be terminated automatically unless both chambers of Congress approved some form of legislative authorization.

Congress could also choose to terminate an unauthorized military operation any time before the 60 days with a concurrent resolution, which doesn’t require a president’s signature – essentially, a “legislative veto.”

And to make sure the president couldn’t stretch the definition of congressional approval, the resolution said neither existing treaties nor new budget appropriations could substitute for legislative authorization of a military action.

Since 1973, actions by all three branches across a variety of political and policy landscapes have undermined its intents and procedures.

Veto vetoed

In 1983, the Supreme Court declared various kinds of legislative vetoes unconstitutional, which led Congress to reinterpret its War Powers Resolution procedures and powers and effectively amend its processes to expedite any joint resolution or bill that “requires the removal of U.S. armed forces from hostilities outside the United States.”

Now, if members want to stop a presidential military campaign already in progress, they must act affirmatively and pass a disapproval resolution, which a president could veto like any other bill. Congress has sent only one such disapproval – to President Donald Trump in his first term – which he vetoed. Congress did not have the two-thirds required in the Constitution to override.

Both chambers of Congress now have to vote twice, once to disapprove a military action and then again to overcome a likely veto, to stop something it never approved in the first place.

House Majority Leader Mike Johnson explains on March 4, 2026, why his party rejects a Democratic-led measure to assert Congress’ war powers and stop the Iran military action.

The 60-day mark for the current Iran operation has therefore loomed as more of a politically charged symbol of this longstanding imbalance on war powers than a real deadline for action by either branch.

Parallels to Kosovo and Libya

The House and Senate have tried to pass legislation to stop military operations against Iran six times since operations began. All attempts have failed, including the most recent vote on April 30. Democrats are considering filing suit against President Trump if operations go beyond 60 days without authorization.

Yet federal courts have long expressed disinterest in getting involved in constitutional questions related to the War Powers Resolution, especially if members of Congress are the plaintiffs.

Although most presidents from Richard Nixon onward have claimed that the War Powers Resolution is an unconstitutional check on their institutional powers, they usually filed the required reports on new military actions 48 hours after they began.

While the current Iran conflict is different in many ways, presidential unilateralism, inconclusive chamber actions and even member lawsuits all echo controversies over U.S. military action in Kosovo in 1999 and Libya in 2011.

Where Trump administration may lean on Clinton

Operation Epic Fury against Iran began Feb. 28, 2026, and President Trump sent the required report to Congress on March 2, 2026.

After detailing the rationale for military action, Trump added “Although the United States desires a quick and enduring peace, it is not possible at this time to know the full scope and duration of military operations that may be necessary.”

He concluded the memo with his interpretation of constitutional power to act unilaterally.

“I directed this military action consistent with my
responsibility to protect Americans and United States interests both at home and abroad and in furtherance of United States national security and foreign policy interests,” the president wrote. He acted, he said, “pursuant to my constitutional authority as Commander in Chief and Chief Executive to conduct United States foreign relations.” He said he made the report “consistent with the War Powers Resolution. I appreciate the support of the Congress in these actions.”

Similarly, on March 26, 1999, President Bill Clinton sent a War Powers Resolution letter explaining his decision two days earlier to take part in a NATO-led operation against the Federal Republic of Yugoslavia, known as FRY.

Clinton wrote to Congress using mostly the same words and phrases Trump did in his 2026 letter. Clinton also said that he took the action “in response to the FRY government’s continued campaign of violence and repression against the ethnic Albanian population of Kosovo.”

A gray-haired man in a dark jacket and blue tie, sitting at a desk in a very formal looking room.
President Bill Clinton after his television address to the nation on the NATO bombing of Serbian forces in Kosovo, March 24, 1999.
Pool/Getty Images

Clinton explained his authority in virtually the same language as Trump and, like Trump, said it was hard to predict how long the operations would continue.

The House and Senate repeatedly failed to either approve or disapprove of Clinton’s actions through a series of votes across March and April 1999. But lawmakers did send him supplemental appropriations for the operations in May.

NATO suspended the operation after 78 days. Almost a year later, a federal appellate court upheld a district court’s decision rejecting a lawsuit led by Rep. Tom Campbell, a California Republican, alleging Clinton violated the War Powers Resolution. Rather than deciding on the merits, the decision rejected the lawmakers’ claims of injury as not reviewable by the court.

Obama did it, too

In a very different context, a similar rhythm played out during President Barack Obama’s presidency.

During the “Arab Spring” revolts of 2010-2011, the U.N. Security Council passed two resolutions condemning violence against Libyan civilians by security forces under the direction of Colonel Moammar Gadhafi.

On March 21, 2011, two days after NATO operations began against Gadhafi’s forces, which included American air support, Obama sent his War Powers Resolution letter to the Republican House and Democratic Senate. Obama had not received prior legislative authority from Congress.

Obama’s letter included language almost identical to Clinton’s earlier letter and Trump’s later one.

As with Kosovo, the House and Senate did not ultimately agree to either approve or disapprove of the president’s actions in support of the UN and NATO over the operation’s 222 days. In addition, Democratic Rep. Dennis Kucinich of Ohio led a group of mostly Republican House members in a failed War Powers Resolution lawsuit to stop the president.

Unilateral action endures

The Office of Legal Counsel in the Department of Justice has published legal opinions that explain and defend presidential war powers, including with Kosovo and Libya. In December 2025, that office published a memo defending the imminent January 2026 capture of Nicolás Maduro. On April 21, 2026, the State Department published a defense of ongoing U.S. actions in Iran.

Within the current dynamics of the War Powers Resolution, until Congress musters bipartisan supermajorities to connect its own institutional ambition with constitutional power, presidents from either party will decide alone if, and when, the country goes to war. Instead of Congress, presidents may heed public opinion and economic indicators, especially in election years.

The Conversation

Jasmine Farrier is affiliated with the American Political Science Association.

ref. Why the 60-day War Powers Resolution deadline doesn’t actually constrain presidents – https://theconversation.com/why-the-60-day-war-powers-resolution-deadline-doesnt-actually-constrain-presidents-281724

How Britain’s housing crisis contributes to its declining healthy life expectancy

Source: The Conversation – UK – By Emma Baker, Professor of Housing Research, Adelaide University

I Wei Huang/Shutterstock

People in the UK are now spending fewer years in good health than they did a decade ago, according to a new analysis by the Health Foundation. The UK now sits near the bottom of a 21-country comparison, ahead only of the US.

A drop in healthy life expectancy is explained through many causes: obesity, alcohol, drugs, suicide, chronic disease, poverty and widening inequality. But one of the most powerful causes sits atop them all: housing. Where and how people live is one of the main factors explaining how health risks are created and distributed across society.

The UK Housing Review is an annual independent review of housing policy and evidence, written by housing experts and published by the Chartered Institute of Housing. Its latest edition, which we contributed to, identifies several interrelated ways that housing affects health.

A key one is affordability – housing costs shape where people can live, whether they can heat their homes, whether they can afford food and transport, whether they can move for work, whether they can leave unsafe or unsuitable housing and whether they live with chronic financial stress.

In the UK, housing costs are high by historical standards and poor housing remains widespread. The review notes that private rents are now at their highest recorded share of earnings, while millions of homes in England still contain serious health and safety hazards.

When housing is unaffordable, people are forced to make tradeoffs. For example, trading affordability for damp or overcrowded homes. They cut back on heating, food, medication, transport and social participation. They move further from public services, work and support networks. Affordability problems also force many people into cheaper, less secure, tenancies.

Poor housing quality directly shapes health. Cold, damp, mould, disrepair, poor ventilation and unsafe homes are directly linked to respiratory illness, cardiovascular risk, mental health problems and reduced wellbeing.




Read more:
Cold homes increase the risk of severe mental health problems – new study


The Building Research Establishment, an independent research organisation, has estimated that poor housing costs the NHS in England £1.4 billion each year. More than half of this is attributed to cold homes, which increase the risk of respiratory illness, cardiovascular problems and poor mental health. They are especially dangerous for older people, babies and people with existing health conditions.

But the wider costs are even greater. Poor sleep, stress, disrupted schooling, insecure work, social isolation and caring strain all affect mental and physical health. They increase pressure on families and, over time, on health, education and social care systems.

Close up of someone resting their hands and hot drink on a radiator
Cold homes can cause serious and widespread health problems.
Jelena Stanojkovic

Historically in the UK, social housing has provided some protection to people unable to access good quality affordable housing in the open market. But the stock of social rented housing in the UK has declined. This means that people are increasingly dependent on (often expensive) market rental, where the quality, size and location of housing depend much more directly on income.

The rise of the private rented sector this century has meant that more households are exposed, not just to higher housing costs, but also to shorter tenancies and fewer protections than social housing traditionally provided.

The Renters’ Rights Act increases security, but does not remove “no fault” evictions altogether and does little to protect tenants from economic pressures that can result in eviction. The cognitive burden of worrying about eviction, arrears, repairs or the next rent increase is a direct health risk.

Recent evidence also suggests that insecure housing can result in measurably faster biological ageing, equivalent to the effects of more traditional health concerns like smoking.

Additional weeks of biological ageing per year from different factors

Bar chart showing additional weeks per year for private renting (2.4 weeks) compared to other social determinants of health including unemployment (1.4 weeks), having no qualifications (1.1 weeks) and being a former smoker (1.1 weeks)

Amy Clair

The number of people living in temporary accommodation has risen dramatically, reaching over 130,000 households at the beginning of 2025. This is a 156% increase compared with 2010, largely driven by the poor affordability and insecurity of the private rented sector and lack of social housing. Temporary accommodation is inadequate housing, particularly for children. Living in temporary accommodation was a contributing factor in the deaths of at least 104 children in England between 2019 and 2025, 76 of whom were under one year of age.

This is not about housing quality alone. Temporary accommodation reflects multiple risks brought together: poverty, overcrowding, poor conditions, instability, lack of space for safe infant sleep, poor access to services and wider racial and social inequality. The National Child Mortality Database identifies temporary accommodation as a contributing factor to vulnerability, ill health or death, not necessarily as the sole cause. Emerging evidence also links temporary accommodation with stillbirth and neonatal death.




Read more:
Insecure renting ages you faster than owning a home, unemployment or obesity. Better housing policy can change this


Housing health inequality

ONS data shows a very large difference in healthy life expectancy between the most and least deprived areas. In 2022-24, healthy life expectancy in the most deprived areas of England was just 49.8 years for men and 48.2 years for women, compared with 69.2 and 68.5 years in the least deprived areas.

Housing contributes to this difference, determining whether people live in homes that support recovery or deepen stress, whether children grow up in stable and safe environments, and whether older people can remain warm and independent.

If the government is serious about its stated aim to “halve the gap in healthy life expectancy between the richest and poorest regions”, housing policy must become health policy.

That means investing in social housing, enforcing decent standards in the private rented sector, making homes warmer, safer and more accessible, and recognising temporary accommodation, overcrowding and insecurity as public health failures, not just housing management problems.

It also means changing the way that success is measured. Housing policy is too often judged by supply numbers, prices or tenure outcomes. These matter, but they are incomplete. A healthy housing system should also be judged by whether people can live in homes that are affordable, secure, decent, suitable and resilient to climate change.

The decline in healthy life expectancy is a warning light. It tells us that the UK is not only failing to keep people well for longer, it is failing to provide the foundations of health.

The Conversation

Emma Baker receives funding from the Economic and Social Research Council, the Australian Research Council, The National Health and Medical Research Council, and the Australian Housing and Urban Research Institute.

Amy Clair receives funding from the Australian Research Council and the Australian Housing and Urban Research Institute.

Mark Stephens receives funding from ESRC, the EU/Innovate UK and the Australian Housing and Urban Research Institute (AHURI).

ref. How Britain’s housing crisis contributes to its declining healthy life expectancy – https://theconversation.com/how-britains-housing-crisis-contributes-to-its-declining-healthy-life-expectancy-281605

Ten compelling poems about climate change – chosen by our experts

Source: The Conversation – UK – By Jack Reid, PhD Candidate in Irish literature, University of Limerick

Three Reading Women in a Summer Landscape by Johan Krouthén (1908). WikiCommons

We asked ten literary experts to recommend the climate poem that has spoken to them most powerfully. Their answers span over 200 years and a range of emotions from sorrow, to anger, fear and hope.

This article is part of Climate Storytelling, a series exploring how arts and science can join forces to spark understanding, hope and action.

1. Death of a Field by Paula Meehan (2005)

Published in the wake of the 2008 financial crisis, Paula Meehan’s Death of a Field critiqued the environmental impact of the Celtic Tiger economy in Ireland.

The poem anticipates the destruction of the titular field by property developers with little regard for native ecologies: “The end of the field as we know it is the start of the estate.”

Death of a Field read by Paula Meehan.

The global effects of the climate crisis are seen from a uniquely local perspective as the displacement of Irish wildlife mirrors the effect of colonial violence. “Some architect’s screen” is simply the latest iteration of imperial technologies that seek to plunder Irish landscapes. The poem gains further strength by refusing to replicate a hierarchical relationship to nature by preserving its many mysteries:

Who can know the yearning of yarrow

Or the plight of the scarlet pimpernel

Whose true colour is orange?

Jack Reid is a PhD Candidate in Irish literature

2. Darkness by Lord Byron (1816)

Darkness imagines the fallout of a volcanic eruption that has destroyed the Earth. The “dream” that the poem mentions was inspired by genuine weather conditions during the “year without a summer” in 1816, caused by the eruption of Mount Tambora in Indonesia the previous year.

Darkness by Lord Byron.

Sulphur in the atmosphere caused darkness and low temperatures across Europe. In Lake Geneva, Lord Byron experienced the infamous “haunted summer” of darkness.

Byron’s depiction of climate catastrophe is bleak, with words like “crackling”, “blazing” and “consum’d” bearing resemblance to contemporary reports of wildfires caused by climate change. After a famine, all elements of Byron’s Earth, from the clouds to the tide, eventually cease to exist: “Seasonless, herbless, treeless, manless, lifeless– / A lump of death – a chaos of hard clay.” Read as a portent of the Anthropocene, Byron’s poem urges readers to seriously consider the future of mankind.

Katie MacLean is a PhD candidate in English Literature

3. Mont Blanc by Percy Bysshe Shelley (1817)

Byron’s close friend Percy Bysshe Shelley was also inspired by the “year without a summer”. He witnessed temperatures drop, volcanic ash hanging heavy in the air and crops failing. While his wife Mary used the gloomy climatic event to inform her novel Frankenstein (1818), Shelley channelled them into his poem Mont Blanc.

A reading of Mont Blanc.

In his ode, Shelley describes a timeless “wall impregnable of beaming ice”. By drawing on his scientific reading, he then explains his fears regarding global cooling and the possibility of vast glaciers eventually covering the alpine valleys.

He imagines “the dwelling-place / Of insects, beasts, and birds” being obliterated and mankind forced to flee. While Shelley saw this process as “destin’d” and inevitable, it is clear that Mont Blanc is a poem with catastrophic climate change at its heart. In 2026, it is difficult to read in any other way.

Amy Wilcockson is a research fellow in Romantic literature

4. Characteristics of Life by Camille T. Dungy (2012)

There’s something gloriously elastic about invertebrates: the spinelessness of a worm, the pulsing of the jellyfish, the curling of an octopus. Spiders, snails and bees, too, with their exoskeletons on display, invite us to see things “inside-out”.

These are the thoughts I have when I read Characteristics of Life by Camille T. Dungy, which opens with a snippet from a BBC news report claiming that “a fifth of animals without backbones could be at risk of extinction”. What would a world be without the “underneathedness” of the snail beneath its shell beneath the terracotta pot in the garden? Or “the impossible hope of the firefly” whose adult lives span only a handful of human weeks?

Camille T. Dungy speaks about nature and poetry.

Dungy speaks from a “time before spinelessness was frowned upon”, and from a world where to dismiss a being as “mindless” (jellyfish have no brains) or even “wordless” would be “missing the point” entirely. As I think of these creatures that dwell beyond our usual line of vision – flying, crawling, tunnelling and swimming – I find my perspective on our beautiful world turning and shifting.

Janine Bradbury is a poet and a senior lecturer in contemporary writing and culture

5. Prayer at Seventy by Vicki Feaver (2019)

One of my favourite poems about climate change is Vicki Feaver’s Prayer at Seventy from her 2019 collection I Want! I Want!.

The speaker’s request of passing her “last years with less anxiety” appears to be denied by a god who first responds by changing her into “a tiny spider / launching into the unknown / on a thread of gossamer” and who, when she begs to “be a bigger / fiercer creature”, turns her into “a polar bear / leaping between / melting ice floes”.

A reading of Prayer at Seventy by Vicki Feaver followed by an explanation by the poet.

Both images present creatures who are in precarious positions, their futures uncertain, reflecting the state of a person contemplating the unknowns of old age and death. But the poem moves beyond the personal. The reference to the melting ice floes is not solely metaphorical: it reminds us that the planet itself is in danger and every living thing is therefore vulnerable – and will be increasingly so.

Julie Gardner is a PhD candidate in literature




Read more:
How poetry can sustain us through illness, bereavement and change


6. Walrus by Jessica Traynor (2022)

Walrus, from Jessica Traynor’s 2022 collection Pit Lullabies expresses the quiet anxiety a mother has for her child in the world of climate breakdown.

While stripping wallpaper from the box room of her house, the poet discovers a mural of the Walrus and the Carpenter from Alice’s Adventures in Wonderland. Traynor takes part of Lewis Carroll’s poem about the Walrus and the Carpenter walking along the beach, eating the vulnerable oysters, and weaves it into her own poem.

Jessica Traynor reading poems from her collection Pit Lullabies.

Carroll’s absurd verse includes what, at that time no doubt, seemed like an impossible image of a “boiling hot” sea. In the 21st century, this is no longer an absurdity, as Traynor knows. She makes a connection with Carroll’s poem, imploring her child:

Sleep as the sun rises and ice melts

and for want of the freeze a walrus

pushes further up a cliff-face.

It’s a complex poem that reimagines a key work of children’s literature, connecting it with the reality of the changing world. All the while the mother keeps her fears at bay for the sake of her child, “brows[ing] washing machines” with a “ball of tears” in her throat.

Ellen Howley is an assistant professor of English

7. Ocean Forest, co-created by the We Are the Possible programme

Ocean Forest is woven out of words, research, ideas and stories shared by scientists, educators, health professionals, youth leaders, writers and artists. They took part in creative writing workshops to co-create the anthology Planet Forest – 12 Poems for 12 Days for the UN Climate Conference in Brazil in 2025.

In the shallows, alert to change,

the minuscule, overlooked creatures

weave between seagrass, and weed –

live their shortened lives.

When ships pass overhead, when sands shift,

fish navigate swell, migrate beyond

where coral’s been bleached, through schools

of silenced whales and barely rooted mangroves

struggling to thrive in darkening water.

Deeper down,

pressure builds, species exist, unaware,

undisturbed. As heat and waves rise there’s hope

the unfound, the unnamed, the unpolluted

in the remotest ocean forests will survive.

Through uniting disciplines and voices the poem takes unexpected shifts. It demonstrates that climate change affects and erodes the habitats that lie beneath the surface and that urgent action is needed to protect disappearing species.

Yet, there is also a glimmer of hope – that in the deepest, darkest parts of the ocean, where temperatures are near freezing and there are bone-crushing pressures, maybe there are creatures that will survive human interference and pollution.

Sally Flint is a lecturer in creative writing and programme lead on the We Are the Possible programme

8. Di Baladna (Our Land) by Emi Mahmoud (2021)

Emtithal “Emi” Mahmoud is a Sudanese poet and activist, who has won multiple awards for her slam poetry performances. Mahmoud performed Di Baladna at the United Nations Climate Change Conference in 2021.

Poetry – especially spoken word – helps people connect emotionally with the human side of climate-driven displacement, a topic that’s often explained only through technical language. The language of emissions targets, temperature thresholds, or policy frameworks can distance people emotionally from its consequences. Yet poetry can cut through this abstraction.

Di Baladna (Our Land) read by Emi Mahmoud.

Mahmoud’s performance gave voice to those forced from their homes by environmental collapse, reminding listeners that climate change is not only an environmental crisis but a deeply human one, with profound effects on individuals, families and communities.

By merging vivid natural imagery with the rhythms of displacement and lived testimony, the poem urges listeners to replace passive awareness with empathy. Mahmoud implores us to feel the loss, fear and resilience of displaced communities, looking beyond news headlines and images of victimisation. Engaging with such work helps transform climate refugees from statistics into people.

Clodagh Philippa Guerin is a PhD candidate in refugee world literature

9. Flowers by Jay Bernard (2019)

At first glance, Jay Bernard’s Flowers is circular poem (one that begins and ends in the same place) but you soon realise that the circle isn’t going to complete. It opens:

Will anybody speak of this

the way the flowers do,

the way the common speaks

of the fearless dying leaves?

And closes:

Will anybody speak of this

the fire we beheld

the garlands at the gate

the way the flowers do?

And the answer seems to be, no: no one will speak of these things – the “coming cold” and the “quiet” it will bring – only the things themselves as they die. With the songs Where Have All the Flowers Gone? by Pete Seeger and Blowin’ in the Wind by Bob Dylan in its DNA, Flowers has the eternal power of a folk-lyric – prophetic and unignorable.

Kate McLoughlin is a professor of English literature

10. Place by W.S. Merwin (1987)

Climate change poetry – should it be a thing? How do poets avoid the oracular pomp it threatens? Browsing my small library I’m shocked anew to realise most poets lived and died blissfully innocent of our condition.

OK, what about the late John Burnside’s lyric Weather Report (“this is the weather, today / and the weather to come”). It poignantly extrapolates from a sodden summer to his sons’ futures: “a life they never bargained for / and cannot alter”. Heartbreaking. Or the odd dread of spring in Fiona Benson’s Almond Blossom, a season characterised as Earth’s, “slow incline … inch by ruined inch”. Ditto.

W.S. Merwin reads Place.

But then I reach back to the great American poet W.S. Merwin’s short prayer Place to find that grace-note of hope which surely needs to thread through all poems, whether they speak of climate change, mortality or love: “On the last day of the world / I would want to plant a tree.” Me too.

Steve Waters is a playwright and professor of scriptwriting at the University of East Anglia

This article features references to books that have been included for editorial reasons, and may contain links to bookshop.org. If you click on one of the links and go on to buy something, The Conversation UK may earn a commission.

The Conversation

Amy Wilcockson receives funding from Modern Humanities Research Association as Research Fellow for the Percy Bysshe Shelley Letters project.

Steve Waters receives funding from AHRC

Clodagh Philippa Guerin, Ellen Howley, Jack Reid, Janine Bradbury, Julie Meril Gardner, Kate McLoughlin, Katie MacLean, and Sally Flint do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. Ten compelling poems about climate change – chosen by our experts – https://theconversation.com/ten-compelling-poems-about-climate-change-chosen-by-our-experts-281698