Seeds of Exchange reveals the untold story of the plant collectors who connected Canton and London in the 18th century

Source: The Conversation – UK – By Max Carter-Brown, Lecturer, Evolutionary Biology, Anglia Ruskin University

I’m standing in a deconsecrated church in Lambeth, London, now home to the Garden Museum. It has a warm and pleasant atmosphere, undeniably a church, yet far removed from its original purpose. On this quiet Friday morning, I met with Emma House, the lead curator of the exhibition Seeds of Exchange. We wandered around the exhibit, which is deceptively small for the scale of its story, crossing continents, cultures, languages and time.

Seeds of Exchange: Canton and London in the 1700s tells a story that is both local and global. It centres on a short-lived but remarkable collaboration between an English botanist and his Chinese counterparts. Together, they documented the plant life of Canton (modern-day Guangzhou) at a time when global trade, science and empires were becoming deeply entangled.

As a botanist I love plants – but this story is not only about them. It is about how knowledge moves, and who gets to shape it.

A meeting point of worlds

The late 18th century was a period of carefully controlled contact between China and Europe. Trade with the outside world in China was tightly regulated through licensed Chinese merchant guilds. Foreign traders could only operate during part of the year.

Into this system stepped John Bradby Blake, an employee of the British East India Company in the early 18th century.

Like many of his contemporaries, he was not simply a passive participant in imperial trade. The East India Company allowed its agents a degree of personal enterprise, and Blake – having suffered substantial financial losses in tea speculation – turned to botany as both scientific pursuit and potential commercial opportunity.

His project was ambitious: to catalogue Chinese plants in what he envisioned as a Compleat Chinensis (Complete Chinese). Between 1766 and his death in 1773, he commissioned over 150 botanical paintings, documenting many now familiar plant species, ranging from citrus fruits and camellias to turmeric and jackfruit.

What makes this project particularly striking is that it was not a solitary European endeavour. Blake relied heavily on local expertise, as he did not know the flora and did not speak Mandarin.

Mak Sau, a Chinese artist about whom we know very little, produced detailed botanical paintings that form the heart of this exhibition. These works are scientific documents, capturing colour and structure with fantastic precision. But they are also superb works of art and form a historically important collection of early botanically accurate watercolour paintings in China.

Local knowledge also helped identify species that Blake himself struggled to classify. Whang At Tong, Blake’s Chinese counterpart, was a merchant operating within the Canton system. He facilitated the exchange of materials, knowledge and, eventually, the transport of Blake’s collection back to Britain. The endeavour was, in many ways, a shared intellectual enterprise. Yet it unfolded within an unequal system shaped by imperial trade and economic ambition.

Plants, profit and empire

Many of the plants depicted in Seeds of Exchange hint at the economic motivations behind Blake’s work. Tea, citrus species, indigo and medicinal plants all had clear commercial value. Others carried horticultural interest that would later shape European gardens.

Blake cultivated plants in his own Canton garden, experimenting with germination and growth and sending seeds back to Britain. These botanical exchanges contributed, in small but significant ways, to breaking China’s monopoly on certain crops – particularly tea.

Yet the paintings also reveal a more complex botanical landscape. Some species, such as chilli peppers and watermelon, were themselves recent arrivals to China (from South America and Africa respectively).

Even in the 18th century, plant distributions were already shaped by centuries of movement across continents. Today, the movement of plants across the world is on a monumental scale, driven by crops and horticulture. The exhibition quietly reminds us that “native” and “foreign” are often more fluid categories than we assume.

Blake’s death in 1773 brought the project to an abrupt halt. He never completed his Compleat Chinensis, and his work might easily have faded into obscurity. Instead, Whang At Tong transported the collection to London, where it entered elite scientific circles. He is one of the earliest recorded Chinese people to have come to the UK. He met figures such as Joseph Banks, a central figure in British botany, and even sat for a portrait by Joshua Reynolds – a rare moment of cultural visibility for a Chinese visitor in 18th-century Britain. The Reynolds painting is in the exhibit, and exquisitely done.

Despite this, the botanical paintings themselves were never fully integrated into British science. Seeds were sent to Kew, but the visual and documentary archive remained largely unused. Over time, the collection became physically divided. One portion, consisting of manuscripts and herbals (historical books describing the properties of plants), ended up, remarkably, in Canterbury Cathedral. Another, including many of the paintings, passed through the art market before being acquired by the Oak Spring Garden Foundation in Virginia in the 20th century.

Reuniting the past

Seeds of Exchange marks the first time these materials have been brought back together in over two centuries. Seen together, the paintings, herbals, notebooks and maps reveal a network of knowledge production that was collaborative, cross-cultural and contingent. Recent research indicates that Blake mainly used texts by European authors for identification, however the exhibition shows Chinese floras which were used in the work, highlighting the depth of local contribution.

The exhibition also sits within a broader historical context. The Garden Museum itself stands on land once associated with early botanical collectors such as the Tradescant family, whose 17th-century “cabinet of curiosities” helped lay the foundations of modern museums. From these early collections to Blake’s Canton project, the gathering and classification of plants has long been tied to exploration, trade and power.

What, then, does this exhibition tell us today? At one level, it is a fascinating story of early globalisation. But it also prompts deeper questions about authorship and recognition. Projects like Blake’s were often framed as European achievements, even when they depended heavily on local knowledge and labour.

Seeds of Exchange highlights that scientific knowledge has almost always been co-produced, even if the historical record has not always acknowledged this. In an era when museums and collections are increasingly reexamining their collections and histories, this matters.

Like the plants it documents, the knowledge this exhibition represents has travelled, adapted and taken root in new contexts – and we are still tracing its origins more than two centuries on.

Seeds of Exchange: Canton and London in the 1700s is at the Garden Museum in London until May 10 2026

The Conversation

Max Carter-Brown 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. Seeds of Exchange reveals the untold story of the plant collectors who connected Canton and London in the 18th century – https://theconversation.com/seeds-of-exchange-reveals-the-untold-story-of-the-plant-collectors-who-connected-canton-and-london-in-the-18th-century-281057

La frontière, épicentre historique du conflit entre l’Afghanistan et le Pakistan

Source: The Conversation – France in French (3) – By Romélien Colavitti, Professeur des universités en droit public, Université de Tours

Coup de projecteur sur la frontière afghano-pakistanaise, où de nouveaux heurts se sont produits au début de l’année 2026.
R. Colavitti, Fourni par l’auteur

La guerre qui a éclaté le 21 février 2026 entre l’Afghanistan et le Pakistan s’inscrit dans la continuité d’un conflit ancien, dont les principales racines remontent à l’époque coloniale et à la délimitation en 1893 de la frontière commune, la fameuse « ligne Durand ».


Au XIXᵉ siècle, le « Grand Jeu » oppose en Asie centrale l’Empire russe, dont le contrôle s’étend jusqu’à l’ancien Turkestan – en terres turkmènes, ouzbèkes et tadjikes – à la couronne britannique, dont la frontière occidentale du British Raj (les Indes britanniques) inclut le fleuve Indus, dans l’actuel Pakistan.

Entre ces deux zones, l’émirat d’Afghanistan était déjà un État souverain, en partie tribal, multi-ethnique à dominante pachtoune et multi-confessionnel à majorité musulmane sunnite.

Une zone tampon entre Empire russe et British Raj

Pour les Britanniques, l’Afghanistan représentait une zone tampon face au risque expansionniste russe. Ils cherchèrent donc à s’en emparer par la force à trois reprises : entre 1839 et 1842, entre 1878 et 1880, puis entre mai et août 1919.

La première guerre (1839-1842) fut remportée par les Afghans sous la direction de Dost Mohammed Khan à la suite de la bataille de Gandamak, en janvier 1842. Les troupes britanniques engagées, ainsi que leurs supplétifs indiens, furent décimés. Seul le docteur William Brydon, chirurgien des armées, survécut et parvint à s’enfuir à dos de cheval pour rapporter son récit aux autorités postées à Jalalabad, dans la province de Nangarhar.

Vestiges d’une armée, peint par Elizabeth Thompson en 1879, représente William Brydon, exténué, revenant du désastre de Gandamak.

La deuxième guerre (1878-1880) fut celle de la revanche. Le Congrès de Berlin de juillet 1878 a été marqué par un rapport de force diplomatique entre l’Empire russe et la couronne britannique pour contrôler les Balkans et l’accès oriental à la Méditerranée. À sa suite, en vue de maintenir une influence en Asie centrale, des émissaires russes furent envoyés à Kaboul auprès de Sher Ali Khan (le fils de Dost Mohammed Khan), ce qui suscita une réaction immédiate de Lord Lytton, vice-roi (britannique) des Indes, qui craignait une collusion russo-afghane. En septembre 1878, Lytton envoya sa propre mission diplomatique dirigée par Neville Bowles Chamberlain à Kaboul, mais celle-ci fut bloquée par les forces afghanes dans la passe de Khyber. L’émir, endeuillé par le décès récent de son jeune fils le prince Abdullah Jan, n’entendait pas faire affront aux Russes en accueillant une représentation britannique qu’il percevait comme colonialiste.

Lytton formula alors un ultimatum : l’Afghanistan devait accepter d’accueillir sa représentation avant novembre 1878, sans quoi il lancerait une offensive. Sans réponse dans ce délai, le conflit éclata et, cette fois, les Britanniques l’emportèrent. Ils obtinrent alors le contrôle de Peshawar (en zone pachtoune) et de Quetta (au Baloutchistan), aux confins des territoires respectifs des belligérants. Cet avantage fut officialisé par le traité de Gandamak, signé le 26 mai 1879 par Louis Cavagnari, représentant britannique, et Mohammad Yaqub Khan (le fils de Sher Ali Khan, décédé à Mazar-e-Sharif dans sa fuite vers la frontière russe).

Deux mois plus tard, en juillet 1879, Cavagnari était installé comme représentant permanent à Kaboul. Mais le Bala Hissar (« Château d’en haut »), siège de l’ambassade britannique, fut rapidement assiégé puis incendié par des mutins afghans réclamant leur solde, le 3 septembre 1879. Cavagnari et l’ensemble de sa représentation furent assassinés.

La réaction de Lytton ne se fit pas attendre. Les troupes britanniques, dirigées par Frederick Roberts, prirent alors Kaboul. Mohammad Yaqub Khan abdiqua le 12 octobre 1879 et s’exila en Inde.

Une guerre civile sous occupation militaire s’ensuivit et les Britanniques soutinrent l’avènement au pouvoir d’Abdur Rahman Khan (neveu de Sher Ali Khan). Celui-ci acceptait, en effet, d’abandonner sa politique extérieure en échange du retrait des troupes et de garanties de conserver le contrôle des affaires intérieures. C’est dans ce contexte que l’Afghanistan et le British Raj furent séparés par une frontière de 2 430 kilomètres, en vertu de l’accord bilatéral du 12 novembre 1893 conclu entre l’émir et Sir Henry Mortimer Durand : la fameuse « ligne Durand », qui sépare encore aujourd’hui l’Afghanistan du Pakistan, était établie. Elle coupait durablement en deux les populations pachtounes au nord et, dans une moindre mesure, baloutches au sud.

La ligne Durand (1893).
National Geographic

La troisième guerre anglo-afghane, entre mai et août 1919, fut déclenchée par le projet afghan de reprise du contrôle territorial des régions tribales. D’abord limité au village de Bagh (dans la région d’Abbottabad), ce projet menaçait de s’étendre rapidement à Peshawar où Amanullah Khan, qui dirigeait alors l’Afghanistan, espérait un soulèvement populaire.

Les Britanniques reprirent le contrôle étendu de la frontière et bombardèrent Kaboul mais, craignant un nouvel enlisement au lendemain du premier conflit mondial, ils conclurent rapidement le traité d’armistice de Rawalpindi, le 8 août 1919, et l’amendèrent le 22 novembre 1921. Ils reconnurent alors la souveraineté afghane dans les limites de la ligne Durand et renoncèrent à étendre leur contrôle territorial. Un soulèvement populaire au Waziristan (côté britannique) n’y fit rien : la frontière était désormais intangible.

Elle survivra à la partition des Indes en 1947 ainsi qu’à la proclamation de la République du Pakistan en 1956, et s’imposera à la reconnaissance internationale. De cette histoire douloureuse naîtront deux conceptions diamétralement opposées de la frontière.

Pour l’Afghanistan, une « frontière-passage »

Du point de vue afghan, les zones tribales pachtounes sous administration fédérale pakistanaise Federally Administered Tribal Areas (FATA), regroupées autour de sept « agences » (Bajaur, Khyber, Kurram, Mohmand, Oraksai, Waziristan du Nord et Waziristan du Sud) et rattachées depuis 2018 à la province de Khyber Pakhtunkhwa, se situent dans le prolongement naturel du territoire national et constituent un passage obligé sur l’axe Kaboul-Jalalabad-Peshawar.

Zones tribales sous administration fédérale (FATA) en 2018/Bureau des Nations unies pour la coordination des affaires humanitaires.
OCHA

Malgré la longueur de la frontière, les points de passage officiels sont rares, le transit de personnes étant souvent informel (comme à Ghulam Khan dans le Waziristan du Nord, Angoor Adda dans le Waziristan du Sud ou Karlachi dans l’agence de Kurram). Au Baloutchistan, les grandes villes sont peu nombreuses et les territoires relativement arides : Chaman (au Pakistan), ville voisine de Spin Boldak (côté afghan, dans la province de Kandahar) est le principal poste-frontière de cette zone.

Mais c’est Torkham, au nord, dans la passe de Khyber, qui est de loin le plus fréquenté par les camions et les voyageurs. C’est ainsi une route commerciale vitale pour l’Afghanistan. La région y est montagneuse : la voie de circulation routière est sinueuse, tandis que le passage pédestre des caravanes traditionnelles s’opère à proximité. Le franchissement de la frontière par transport ferroviaire n’est plus permis, la ligne, désormais vétuste, datant de 1925.

Le col de Khyber.
James Mollison/Wikipédia, CC BY-ND

Dans L’Usage du monde (1963), l’écrivain-voyageur genevois Nicolas Bouvier relate ainsi son passage en ces lieux, le 5 décembre 1954 :

« Après un an et demi de voyage, j’ai atteint le pied de la passe. La lumière touchait la base des monts Suleiman et le fortin de la douane afghane noyé dans un bouquet de saules qui brillaient comme écailles au soleil. Pas d’uniformes sur la route barrée par un léger portail de bois. Monté jusqu’au bureau. J’ai enjambé les chèvres étendues sur le seuil et passé la porte. Le poste sentait le thym, l’arnica, et bourdonnait de guêpes. L’éclat bleu des revolvers accrochés contre le mur avait beaucoup de gaieté. Assis droit à une table derrière une bouteille d’encre violette, un officier me faisait face. Ses yeux […] étaient clos. À chaque inspiration j’entendais craquer le cuir neuf de son ceinturon. Il dormait. Sans doute un ouzbek de Bactriane, aussi étranger que moi ici. J’ai laissé mon passeport sur la table et suis allé déjeuner. Je n’étais pas pressé. On ne l’est pas quand il s’agit de quitter un pays pareil. »

Depuis lors, et tout le long de la frontière, le transport routier de marchandises s’est déployé quotidiennement, l’économie afghane étant particulièrement dépendante du commerce avec son voisin.

Pour le Pakistan, une « frontière-barrière »

Côté pakistanais, la frontière a fait l’objet de contrôles accrus et de fermetures périodiques (à l’occasion de la rupture des relations diplomatiques entre les deux États dans les années 1960 ou lors de l’invasion de l’Afghanistan par l’Union soviétique dans les années 1980) ainsi que de réouvertures temporaires (lors de la première prise de pouvoir des talibans en Afghanistan dans les années 1990), jusqu’à devenir une barrière de plus en plus difficilement franchissable.

Au lendemain du 11 septembre 2001, le gouvernement pakistanais a ainsi entendu empêcher l’infiltration sur son territoire des combattants d’Al-Qaida et des talibans fuyant l’offensive de la coalition occidentale. En 2003, puis en 2006-2007 et en 2008, des tensions diplomatiques bilatérales accompagnées d’affrontements endémiques ont conduit à la fermeture temporaire des postes-frontières stratégiques de Chaman et de Torkham, à la mise en place de contrôles biométriques et à la construction de tronçons de barrières contrôlées militairement.

Si la lutte contre le terrorisme était présentée comme l’objectif principal, il s’agissait aussi pour Islamabad d’empêcher le narcotrafic et, de manière moins assumée, de stopper l’afflux de déplacés afghans fuyant la guerre entre la coalition occidentale et les talibans, voire de faciliter leur retour forcé.

Après le retrait des troupes occidentales d’Afghanistan et la reprise du pouvoir par les talibans durant l’été 2021, la tension n’a cessé de croître jusqu’à la déclaration d’une « guerre ouverte » par Khawaja Asif, le ministre pakistanais de la défense, le 26 février 2026. En cause, les talibans pakistanais du mouvement Tehrik-e Taliban Pakistan (TTP), soutenus par les talibans afghans et les terroristes de l’État islamique au Khorassan, EI-K. Un attentat suicide revendiqué par l’État islamique (EI) puis imputé par le Pakistan au TTP et à l’EI-K, le 6 février 2026, avait visé la mosquée chiite Khadija Tul Kubra de Tarlai Kalan, au sud-est d’Islamabad, et fait plus d’une trentaine de morts.

En représailles, à compter du 21 février 2026, le Pakistan a bombardé plusieurs sites réputés abriter des factions terroristes, notamment dans la province de Nangarhar. Après que l’Afghanistan eut à son tour attaqué des postes-frontières, le Pakistan a alors lancé, le 26 février 2026, l’opération « Ghazab Lil-Haq » (« Fureur juste »), frappé Kaboul le lendemain, par la voie aérienne, ainsi que Kandahar, lieu de résidence du chef spirituel des talibans, le mollah Haibatullah Akhundzada, et les provinces de Nangarhar, Paktia, Paktika ou Laghman. Depuis lors, les échanges de tirs n’ont pas cessé.

Si les cibles officielles sont des camps retranchés du TTP, la Mission d’assistance des Nations unies en Afghanistan (Manua) et les organisations non gouvernementales (notamment Amnesty International) ont recensé plusieurs centaines de morts (combattants et civils) et des milliers de déplacés. Une frappe sur un centre de réhabilitation pour toxicomanes (dans l’enceinte de l’ancien camp Phoenix) à Kaboul, le 16 mars 2026, aurait ainsi fait 143 morts auxquels s’ajoutent les 76 victimes civiles déjà répertoriées en Afghanistan. Cette frappe aurait été effectuée en réaction au décès de quatre civils, la veille, dans le district de Bajaur, et d’un enfant, le 8 mars, dans le Waziristan du Nord, après des tirs de mortier en provenance d’Afghanistan.

La médiation chinoise ouverte à Urumqi (Xinjiang) début avril, après celle diligentée par le Qatar, la Turquie et l’Arabie saoudite, laisse entrevoir un possible dialogue, malgré la fragilité de la situation sur le terrain. En attendant, ce conflit frontalier, aux racines historiques profondes, continue de plonger les civils afghans dans la grave crise humanitaire qu’ils subissent depuis le retour au pouvoir des talibans.

The Conversation

Romélien Colavitti est assesseur à la Cour nationale du droit d’asile. Les propos tenus dans cet article sont personnels et n’engagent pas l’institution.

ref. La frontière, épicentre historique du conflit entre l’Afghanistan et le Pakistan – https://theconversation.com/la-frontiere-epicentre-historique-du-conflit-entre-lafghanistan-et-le-pakistan-280865

La passe d’armes entre Donald Trump et le pape Léon XIV, nouvel épisode d’une querelle millénaire entre pouvoir sacré et pouvoir séculier

Source: The Conversation – in French – By Joëlle Rollo-Koster, Professor of Medieval History, University of Rhode Island

Le pape Léon III couronna Charlemagne empereur le jour de Noël de l’an 800. (Illustration tirée des *Chroniques de Saint-Denis*.) Levan Ramishvili/Flickr via Wikimedia Commons

Derrière la polémique entre le président Trump et le pape Léon XIV se rejoue une question ancienne : qui peut parler au nom de Dieu, et qui fixe les limites du pouvoir ?


Aux États-Unis, l’inquiétude suscitée par l’escalade verbale entre le président Donald Trump et le pape Léon XIV se propage à une vitesse remarquable, du New York Times au Daily Beast et jusqu’aux chaînes de télévision locales. Depuis le début de la guerre en Iran, le pape a appelé à plusieurs reprises à la paix au Moyen-Orient, affirmant que « Dieu ne bénit aucun conflit » et met en garde contre « l’illusion de toute-puissance » qui alimente la guerre.

Le 12 avril 2026, dans une longue publication sur son réseau social, Donald Trump a tourné en dérision Léon XIV, l’estimant « FAIBLE face à la criminalité et désastreux en matière de politique étrangère » et lui enjoignant de « se concentrer sur le fait d’être un grand pape, pas un homme politique ». Sur son compte Truth Social, un portrait du président états-unien, réalisé par IA, où il apparaît, semblable au Christ, en train de guérir un homme, a été publié puis supprimé.

Au cœur de cette querelle publique se trouve une question ancienne : un chef religieux peut-il contester le pouvoir politique, en particulier celui du dirigeant de l’un des pays les plus puissants du monde ?

En qualité d’historienne médiéviste ayant dirigé l’édition de la Cambridge History of the Papacy (non traduit en Français), je ne peux m’empêcher d’y voir un schéma familier.

Pour beaucoup, la sortie de Donald Trump contre le pape Léon XIV est choquante. Mais les conflits entre papes et dirigeants ne sont pas une anomalie : ils constituent une caractéristique durable de l’histoire occidentale. Chaque fois que des responsables politiques habillent leur pouvoir d’un langage sacré ou que des dirigeants religieux dénoncent publiquement la violence politique, ils rejouent des débats vieux de plus d’un millénaire.

Ces affrontements ne sont pas seulement symboliques : ils portent sur la question de savoir qui détient l’autorité ultime sur les humains, sur les âmes – et, en fin de compte, sur l’histoire elle-même.

Deux pouvoirs, étroitement liés

Dès ses premiers siècles, le christianisme est intimement lié au politique. L’empereur romain Constantin Ier en autorise la pratique dans l’Empire en 313. Il préside ensuite le concile de Nicée, une assemblée théologique majeure, brouillant la frontière entre pouvoir politique et autorité spirituelle.

Au Vᵉ siècle, le pape Gélase Ier formule une vision concurrente : le monde serait gouverné par deux pouvoirs, sacerdotal et royal. En dernière instance, soutient-il, l’autorité spirituelle l’emporte sur le pouvoir politique, car elle promet le salut éternel. La théorie de Gélase ne résout pas la tension entre les deux, mais elle pose un cadre durable pour la pensée politique chrétienne.

La relation entre ces deux pouvoirs connaît un tournant décisif en l’an 800, lorsque le pape Léon III couronne Charlemagne empereur, le jour de Noël. Cet acte n’est pas seulement cérémoniel : il implique que l’autorité impériale en Occident provient de l’Église et que la légitimité politique nécessite l’aval du pape.

Ce couronnement fait suite à des années d’instabilité politique à Rome et à une dépendance croissante de la papauté envers les Francs pour sa protection militaire. Après son élection en 795, Léon III est attaqué par ses opposants et trouve refuge à la cour de Charlemagne. Le roi revient à Rome à ses côtés et y réaffirme sa légitimité. En retour, Léon III couronne Charlemagne. Par ce geste, il affirme son propre rôle de faiseur d’empereurs tandis que Charlemagne acquiert une aura sacrée.

Ce moment reconfigure profondément la théologie politique médiévale. Il incite les souverains à se considérer comme les garants à la fois de l’ordre politique et de l’orthodoxie religieuse tandis que les papes passent du rôle de conseillers spirituels à celui d’acteurs engagés dans le gouvernement séculier.

Il en résulte un paradoxe : les rois invoquent Dieu pour sanctifier la conquête, comme Charlemagne lors de ses guerres brutales contre les Saxons, mais, dans le même temps, l’Église entend contenir la violence, encourageant les guerres justes et menaçant les comportements violents de sanctions spirituelles.

La querelle des Investitures

Au XIᵉ siècle, cependant, la papauté cherche de plus en plus à s’affranchir de la domination séculière. En particulier, les papes veulent nommer eux-mêmes les évêques, plutôt que de laisser faire la noblesse ou le roi.

Ce conflit éclate avec la querelle des Investitures, l’un des affrontements les plus décisifs du Moyen Âge, et pose des bases essentielles pour la Magna Carta, premier texte à soumettre le pouvoir royal à la loi. Ces deux épisodes répondent à une même question fondamentale : qui a le droit de conférer l’autorité, et quelles limites s’imposent au pouvoir politique ?

Un dessin au trait en noir et blanc montre deux hommes assis, vêtus de robes. L’un porte une couronne, tandis que l’autre a une auréole autour de la tête
Une gravure sur bois représente un roi au Moyen Âge investissant un évêque des insignes de sa fonction, notamment la crosse, son bâton pastoral.
Philip Van Ness Myers/ReneeWrites via Wikimedia Commons, CC BY

Il ne s’agit pas seulement d’administration ecclésiastique, mais bien de la souveraineté elle-même. Les évêques sont de grands propriétaires fonciers et des acteurs politiques de premier plan ; contrôler leur nomination revient à contrôler leur richesse, leur fidélité et le gouvernement. En cherchant à nommer les évêques, les papes affirment que l’autorité spirituelle relève exclusivement de l’Église, contestant l’idée que les rois exercent un pouvoir sans limite. Il s’agit d’une tentative décisive de dissocier la légitimité spirituelle du contrôle royal et d’imposer des contraintes morales à des souverains qui se réclament d’une autorité divine.

La querelle des Investitures se prolonge pendant plusieurs décennies. Finalement, en 1122, le pape Calixte II et l’empereur Henri V signent le concordat de Worms.

L’accord reconnaît au pape le droit de nommer les évêques et de leur conférer leur autorité spirituelle. L’empereur, de son côté, les « investit » de leurs « temporalités » : c’est-à-dire des pouvoirs temporels attachés à leur charge, tels que les terres, les revenus, la juridiction et les pouvoirs de contrainte.

Contenir le pouvoir du roi

Un siècle plus tard, la Magna Carta poursuit un objectif parallèle.

Son contexte immédiat se trouve dans le conflit autour du nouvel archevêque de Canterbury, que le pape Innocent III avait nommé en 1207. Le roi Jean sans Terre s’y oppose, poussant le pape à l’excommunier et à jeter l’interdit sur l’Angleterre, ce qui signifie que les Anglais ne peuvent plus participer aux sacrements de l’Église.

Pour apaiser les tensions, Jean sans Terre remet en 1213 le royaume d’Angleterre au pape Innocent III, et transforme le pays en un fief pontifical. En échange, il obtient l’approbation papale de mener une guerre contre la France. Mais cet arrangement suscite une profonde colère chez les barons anglais, qui se retrouvent désormais soumis non seulement à leur roi, mais aussi à l’autorité du saint-père. À Bouvines (1214), Jean fait face aux barons rebelles sur son propre territoire.

Le résultat est la Magna Carta, la « Grande Charte ». Imposée au roi par la force des armes, elle affirme qu’il est lui-même soumis à la loi. Elle limite l’autorité royale en matière de fiscalité, de justice et de châtiment, et proclame notamment qu’aucun homme libre ne peut être emprisonné ni privé de ses droits sans un jugement légal.

Jean sans Terre fait alors appel au pape Innocent III, qui annule la charte peu après sa promulgation. Malgré ce revers, la Magna Carta survit : le fils de Jean, Henri III, la réédite à plusieurs reprises, sa version définitive étant mise en œuvre en 1225.

Prendre du recul

À cette aune historique, l’affrontement entre Donald Trump et le pape Léon XIV apparaît moins surprenant. Lorsqu’un président mobilise un langage ou des images sacrées pour justifier la violence, et qu’un pape répond en niant toute caution divine, ils rejouent un affrontement aussi ancien que la chrétienté médiévale : qui peut parler au nom de Dieu, et qui peut fixer des limites au pouvoir ?

Le monde médiéval n’a pas résolu cette tension, mais il a appris à vivre avec en fragmentant l’autorité : d’abord entre l’Église et la couronne, puis entre les souverains et la loi. Ce qui inquiète aujourd’hui, c’est la facilité avec laquelle des dirigeants modernes recourent encore au langage religieux pour échapper aux contraintes et à la fragilité apparente des institutions censées les contenir.

The Conversation

Joëlle Rollo-Koster 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. La passe d’armes entre Donald Trump et le pape Léon XIV, nouvel épisode d’une querelle millénaire entre pouvoir sacré et pouvoir séculier – https://theconversation.com/la-passe-darmes-entre-donald-trump-et-le-pape-leon-xiv-nouvel-episode-dune-querelle-millenaire-entre-pouvoir-sacre-et-pouvoir-seculier-280831

Sécurité alimentaire : pourquoi la paix se joue aussi dans les champs

Source: The Conversation – in French – By Pape Abdoulaye Seck, chercheur, Académie nationale des sciences et techniques du Sénégal (ANSTS)

Alors que les conflits continuent de faire des milliers de victimes dans plusieurs régions du monde, une question reste largement sous-estimée dans l’analyse des crises contemporaines : le rôle central joué par la sécurité alimentaire dans la construction d’une paix juste et durable.

La paix mondiale ne se joue pas seulement sur les champs de bataille ou dans les salles de négociation diplomatique. Elle se joue aussi dans les champs agricoles et dans la capacité des sociétés à nourrir dignement leurs populations.

Mais une question fondamentale mérite d’être posée : de quelle paix parlons-nous réellement ? S’agit-il d’une paix provisoire, réduite au silence des armes et à l’arrêt momentané des hostilités ? Ou bien d’une paix véritable, enracinée dans la justice, la dignité humaine et la capacité des sociétés à offrir à leurs populations les conditions minimales d’une existence digne ?

Mes travaux portent principalement sur les systèmes alimentaires, la sécurité alimentaire, le développement rural et les transformations des agricultures africaines, entre autres. Ma conviction est que la paix durable ne peut se réduire à une simple absence de guerre. Elle est un processus complexe et multidimensionnel.

Cette réalité renvoie à un principe fondamental du droit international. La Déclaration universelle des droits de l’homme de 1948 affirme, dans son article 25, que toute personne a droit à un niveau de vie suffisant lui assurant notamment l’alimentation, la santé et le bien-être. Ce rappel n’est pas anodin. Il signifie que la dignité humaine commence par la capacité à se nourrir correctement.

La faim, un problème politique

Un peuple qui a faim ne peut ni apprendre sereinement, ni travailler efficacement, ni construire un avenir stable. La faim fragilise les sociétés. Elle nourrit les frustrations, les tensions sociales, les migrations contraintes et parfois même les conflits. L’insécurité alimentaire devient ainsi une fabrique silencieuse d’instabilité.

L’économiste Amartya Sen l’a démontré avec force dans Poverty and Famines (1981). Selon lui, les famines ne résultent pas uniquement d’un déficit de production agricole. Elles sont souvent le produit de défaillances institutionnelles, économiques et politiques qui empêchent certaines populations d’accéder à la nourriture disponible.

La faim est donc bien plus qu’un problème agricole : elle est profondément politique.

Un exemple concret illustre parfaitement cette réalité : celui du Brésil au début des années 2000. Sous l’impulsion du président Luiz Inácio Lula da Silva, le pays a lancé en 2003 le programme Fome Zero (Faim Zéro), fondé sur une approche intégrée combinant politiques sociales, soutien à l’agriculture familiale et amélioration de l’accès à l’alimentation.

À travers notamment le programme Bolsa Família (Bourses familiales), des transferts monétaires ciblés ont permis de renforcer le pouvoir d’achat des ménages les plus vulnérables. Parallèlement, des politiques publiques ont soutenu les petits producteurs en facilitant leur accès au crédit, aux marchés et aux programmes d’achats publics, notamment pour l’alimentation scolaire.

Les résultats ont été significatifs. En une décennie, le Brésil a fortement réduit la pauvreté extrême et la faim. En 2014, le pays est même sorti de la « carte mondiale de la faim » établie par la FAO.

Ce succès confirme que la faim n’est pas une fatalité. Elle peut être combattue efficacement lorsque la volonté politique, la cohérence des politiques publiques et l’approche systémique sont réunies.




Read more:
Nourrir l’humanité sans détruire la planète : pourquoi la durabilité alimentaire devient un critère de civilisation


Aujourd’hui encore, les chiffres témoignent de l’ampleur du défi. Le rapport 2023 sur l’état de la sécurité alimentaire et de la nutrition dans le monde, publié conjointement par la FAO, le Fonds international de développement agricole (FIDA), le Fonds des Nations Unies pour l’enfance (UNICEF) et le Programme alimentaire mondial (PAM), estime qu’environ 735 millions de personnes souffrent de la faim.

Ce constat est également souligné par l’économiste Jeffrey Sachs, qui rappelle dans The End of Poverty (La Fin de la pauvreté) que la lutte contre la pauvreté extrême et la faim constitue une condition essentielle de la stabilité mondiale et de la réalisation des Objectifs de développement durable (ODD).

Dans un tel contexte, croire que la paix peut être durable sans résoudre la question alimentaire relève de l’illusion.

La sécurité alimentaire constitue ainsi un pilier stratégique de la paix mondiale. Garantir un accès équitable à une alimentation suffisante et de qualité, c’est renforcer la résilience des sociétés et réduire les facteurs structurels d’instabilité.

Sécurité des personnes et des biens

Cependant, la sécurité alimentaire, aussi fondamentale soit-elle, ne peut à elle seule garantir la paix. Une paix véritable repose également sur d’autres piliers essentiels.

Elle suppose d’abord la sécurité des personnes et des biens. Les citoyens doivent pouvoir vivre, circuler, entreprendre et éduquer leurs enfants sans peur permanente. Là où règnent l’insécurité et la violence, la confiance disparaît et le tissu social se fragilise.

La paix durable exige également des institutions légitimes, transparentes et respectueuses de la volonté populaire. Lorsque les citoyens se reconnaissent dans leurs institutions et perçoivent leur action comme juste et équitable, la stabilité politique se renforce.

L’égalité des chances constitue un autre levier fondamental de cohésion sociale. Une société qui ferme les portes de l’éducation, de l’emploi ou de la mobilité sociale à une partie de sa jeunesse prépare ses propres fractures.

Il en va de même pour l’inclusion des femmes et des jeunes dans la vie économique, sociale et politique. Ces forces vives représentent un formidable potentiel de transformation pour les sociétés.

Une gouvernance responsable

Enfin, la paix durable exige une gouvernance responsable, capable de mobiliser la science, l’innovation et la coopération internationale au service du développement humain.

Dans un monde confronté à des défis majeurs tels que le changement climatique, la pression démographique et les tensions géopolitiques, la question alimentaire devient plus que jamais stratégique.

Produire davantage, produire mieux et garantir un accès équitable à l’alimentation constituent des impératifs essentiels pour l’avenir de l’humanité.

À cet égard, l’expérience de la « révolution verte », portée notamment par l’agronome Norman Borlaug, prix Nobel de la paix en 1970, rappelle combien les progrès scientifiques peuvent contribuer à prévenir les crises alimentaires et à renforcer la stabilité des sociétés.

Au fond, une vérité simple traverse l’histoire des civilisations : un monde incapable de nourrir dignement ses peuples prépare inévitablement ses propres crises. À l’inverse, un monde qui place la sécurité alimentaire au cœur de ses priorités crée les conditions les plus solides d’une paix juste et durable.

La paix mondiale ne se négocie pas seulement dans les enceintes diplomatiques.
Elle se cultive aussi dans les champs.

The Conversation

Pape Abdoulaye Seck 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. Sécurité alimentaire : pourquoi la paix se joue aussi dans les champs – https://theconversation.com/securite-alimentaire-pourquoi-la-paix-se-joue-aussi-dans-les-champs-281036

Coral reefs are secretly connected across vast oceans – and that’s crucial for their survival

Source: The Conversation – Global Perspectives – By Kate Marie Quigley, DECRA Research Fellow in molecular ecology, James Cook University

Lord Howe Island lies in the middle of the ocean, about 700 kilometres northeast of Sydney. It’s covered in lush forest and fringed by the world’s most southerly coral reef ecosystem.

This reef system isn’t as famous as its northern neighbour, the Great Barrier Reef. Our new research in the Journal of Applied Ecology, shows it plays an outsized role in keeping vast coral regions across the Pacific connected – and alive.

A small number of other reefs in the region serve a similar function. Knowing which reefs matter most for recovery and adaptation to ocean warming – and protecting them now – could make the difference between regional reef collapse and long-term resilience.

Tiny coral babies in a vast ocean

Coral reefs are in global decline, but this loss is not just about dying corals – it’s about breaking the natural connections that allow reefs to recover after marine heatwaves, cyclones and other threats.

Right now, climate change is rapidly reducing the ability of coral larvae to travel between reefs, shrinking their chances of survival by undercutting recovery.

These tiny coral babies can sometimes spend many weeks in the surface waters of the open ocean, carried by currents across hundreds or even thousands of kilometres before settling and beginning to grow.

The movement of larvae provides a constant source of replenishment for reefs, both near and far away, which is especially important when reefs are damaged.

Without this constant replenishment, some damaged reefs simply cannot recover. Connectivity isn’t a nice-to-have for coral reefs. It’s their lifeline.

Tracking dispersal across 850 reefs

Our study used ocean circulation models to simulate the trajectories of coral larvae across the southwestern Pacific Ocean from 2011 to 2024, tracking the movement of larvae across 850 reefs.

These reefs spanned the Great Barrier Reef, New Caledonia, the Coral Sea and Lord Howe Island.

We traced how two key coral growth forms (fast-growing branching corals and slower-growing massive corals) move between reefs under current conditions and under projected global climate warming scenarios of 1°C, 2.5°C and 4°C above pre-industrial temperatures.

We then examined how corals moved between different types of reef, including reefs that were naturally resistant to heat stress, those that recover quickly after disturbance, and those that stay cooler because of local water currents and upwelling that naturally reduce water temperature around the reef.

This allowed us to ask not just which reefs are connected, but which kinds of reefs are sending and receiving different types of larvae.

A fragile network

We found that only a handful of reefs act as genuine hubs — places where larvae both arrive from distant sources and depart to “seed” reefs far away. Lose these stepping stones, and the entire network begins to fragment.

The Coral Sea reefs emerged as crucial bridges in this network, linking the southern Great Barrier Reef with New Caledonia and beyond. But perhaps the most striking finding involves Lord Howe Island.

Our modelling identified Lord Howe as a potential refugium: a place where corals may be able to persist even as warming intensifies, potentially owing to its more temperate, southerly position.

A coral reef lagoon with a large rocky mountain in the background.
Lord Howe Island is home to the world’s most southern coral reef ecosystem.
Dylan Shaw/Unsplash

Yet its very isolation – what makes it a likely survivor – also means it has limited natural connectivity with surrounding reefs.

This situation therefore cuts both ways: while isolation helps protect its coral from extreme heat stress, it also means the reef relies less on new larvae that others could need for recovery. It therefore also means Lord Howe needs protection – not just for itself, but for the entire regional reef system that may one day depend on it.

Another important finding is that the reefs most resistant to heat stress (those classified as naturally resistant) tended to export larvae to a relatively smaller number of reefs within the wider network.

But there are techniques that enable the intentional movement of larvae from heat-tolerant reefs to more vulnerable locations. These include assisted gene flow, in which scientists deliberately move warm-adapted adult corals or their offspring to reefs that are more vulnerable to heat stress, helping to spread heat-tolerant genes more quickly across reef networks.

Protecting our marine superhighways

Our results make clear that marine protected areas should not be managed as isolated reserves but as an interconnected network, with transboundary cooperation between Australia and Pacific Island nations.

The larval corridors linking the southern Great Barrier Reef, New Caledonia and Lord Howe Island do not fall within national boundaries. Neither can our conservation response.

Reefs are already fighting against warming oceans. The waters of the Lord Howe Rise and South Tasman Sea, the vast oceanic region between Australia and New Zealand through which these larval corridors flow, are under threat from industrial fishing.

Industrial fishing, pollution and climate change are pushing these ecosystems to the brink, with longlines intersecting surface waters. This cumulative pressure across these newly identified larval transport superhighways adds yet another layer of pressure onto these already stressed ecosystems.

Our research adds a new and crucial dimension to high seas protection. Our region sits directly across the larval corridors that connect and sustain coral reef systems. Protecting this ocean is not just about what lives here. It is about what passes through – fundamental for migratory and connected populations.

The least we can do is protect the superhighways through which their future flows – invisibly, at the ocean surface, some larvae no bigger than a grain of rice, carrying the genetic potential to rebuild what we stand to lose.

The Conversation

Kate Quigley receives funding from the Australian Research Council and Minderoo Foundation. She is also Principal Research Scientist at Minderoo Founation.

Elise Thérèse Gisèle Dehont 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. Coral reefs are secretly connected across vast oceans – and that’s crucial for their survival – https://theconversation.com/coral-reefs-are-secretly-connected-across-vast-oceans-and-thats-crucial-for-their-survival-278424

Whale strandings draw emotional responses. But repeated rescues can cause more harm

Source: The Conversation – Global Perspectives – By Karen Stockin, Professor of Marine Ecology, Te Kunenga ki Pūrehuroa – Massey University

Rescuers placing wet towels on ‘Timmy’, the whale stranded near Wismar, Germany. Morris MacMatzen/Getty Images

A humpback whale repeatedly restranding in shallow waters in the Baltic Sea for more than three weeks has become the focus of a complex debate about reconciling compassion for animals with ethical, evidence-based decision making.

Affectionately known as Timmy, the whale restranded several times and has been growing weaker, failing to recover despite multiple rescue attempts.

Its struggle attracted global attention and triggered debates between experts and the public regarding intervention versus allowing a natural end.

Marine biologists and veterinarians observing the whale made a clear and evidence-based assessment earlier this month: further intervention was unlikely to succeed and would risk prolonging the animal’s suffering.

Yet public pressure – driven by empathy amplified by social media and sharpened into outrage – led German state authorities to permit renewed rescue efforts this week, framed as a “last ditch” effort.

At first glance, it seems an act of compassion. But beneath the surface lies a more difficult truth. As our research shows, when scientific advice is sidelined in favour of public sentiment, outcomes for the very animals we aim to protect can worsen.

The emotional pull of “doing something”

Large, charismatic animals like whales evoke powerful emotional responses. They are intelligent, expressive and visibly vulnerable when stranded.

For many people, choosing not to intervene feels morally unacceptable, with inaction often perceived as neglect.

Wildlife medicine, however, does not operate on instinct or optics. It relies on probabilities, welfare assessments and the recognition that intervention is not always beneficial.

In Timmy’s case, experts from the German Oceanographic Museum and the Institute for Terrestrial and Aquatic Wildlife Research, as well as international organisations, reached a consistent conclusion that the whale was unlikely to survive.

After repeated failed rescues, the environment minister for Germany’s state of Mecklenburg-Western Pomerania determined that continued intervention would likely worsen the whale’s condition. By then, Timmy was showing clear signs of trauma and exhaustion.

The decision was not made in isolation. In early April, the International Whaling Commission’s stranding expert panel publicly supported the German authorities. It outlined that further rescue attempts would likely increase suffering without improving survival chances.

Euthanasia, frequently suggested as an alternative, was deemed impractical, however. The whale’s partial buoyancy, combined with logistical, safety and personnel challenges meant this was not a viable option.

New Zealand’s experience

In 2021, New Zealand experienced a similar situation with Toa, a stranded orca calf.

The response was extraordinary, mobilising national and international expertise. Veterinarians, marine mammal scientists and stranding specialists contributed to an unprecedented rescue effort.

The scientific consensus, however, was sobering. Given Toa’s young age (unweaned), prolonged separation from his pod, and the challenges of reintegration, his chances of survival were extremely low.

Over time, his welfare declined during extended human care. Many experts ultimately supported euthanasia as the most humane option.

That path was not taken. Driven by public hope and attention, efforts continued. Toa died after weeks in care. In retrospect, the case raised a difficult but necessary question: when expert consensus and public sentiment diverge, which should guide decisions?

When perception overrides expertise

This tension is not anecdotal; it is well documented. Research shows that human perceptions and emotional investment can significantly shape responses to cetacean strandings, sometimes directly conflicting with recommendations based on the animal’s wefare.

In high-profile cases, decision making can shift from expert-led processes to outcomes shaped by public pressure. The patterns observed in Germany – repeated strandings, declining condition and cumulative stress – are strong predictors of poor outcomes, regardless of continued intervention.

The disconnect is clear. Experts assess welfare through measurable physiological, behavioural and environmental markers to infer the mental state of an animal. The public often evaluates it through effort, visibility and intent. The result is a compelling but flawed assumption: that doing more means doing better.

A common principle in veterinary ethics is that the ability to intervene does not justify doing so. Every rescue attempt carries risks: handling stress, injury, prolonged suffering and the diversion of limited resources.

While financial cost is often highlighted, the more critical issue is animal welfare. In repeated stranding cases, the ethical balance becomes increasingly stark.

When recovery is highly unlikely, continued intervention can shift from care to harm. In repeated stranding cases, the ethical calculus becomes sharper. Yet this is precisely the moment when public pressure tends to intensify.

A more difficult kind of care

Compassion is not the problem; it is fundamental to conservation. But compassion without evidence can mislead.

What’s at stake is trust in scientific expertise, veterinary judgement and the difficult reality that the most humane decision is not always the most emotionally satisfying one.

If every high-profile stranding becomes a referendum driven by public pressure, we risk creating a system where decisions are shaped less by animal welfare and more by public visibility.

The instinct to rally around a stranded whale reflects the best of human empathy. But real care in wildlife conservation is not always about action. Sometimes, it requires restraint.

In Toa’s case, official documents later revealed most experts had recommended euthanasia to prevent prolonged suffering.

Timmy’s situation raises a similar question. Not whether people care enough, but whether we are willing to accept that caring also means listening to science, to experience and to the difficult truths they bring.

The Conversation

Karen Stockin is the ethics chair for the Society for Marine Mammalogy and a member of the IWC strandings expert panel.

ref. Whale strandings draw emotional responses. But repeated rescues can cause more harm – https://theconversation.com/whale-strandings-draw-emotional-responses-but-repeated-rescues-can-cause-more-harm-281137

How does imagination really work in the brain? New theory upends what we knew

Source: The Conversation – Global Perspectives – By Thomas Pace, Researcher and Lecturer at the Thompson Institute, University of the Sunshine Coast

Grandfailure/Getty Images

Your brain is currently expending about a fifth of your body’s energy, and almost none of that is being used for what you’re doing right now. Reading these words, feeling the weight of your body in a chair – all of this together barely changes the rate at which your brain consumes energy, perhaps by as little as 1%.

The other 99% is used on the activity the brain generates on its own: neurons (nerve cells) firing and signalling to each other regardless of whether you’re thinking hard, watching television, dreaming, or simply closing your eyes.

Even in the brain areas dedicated to vision, the visuals coming in through your eyes shape the activity of your neurons less than this internal ongoing action.

In a paper just published in Psychological Review, we argue that our imagination sculpts the images we see in our mind’s eye by carving into this background brain activity. In fact, imagination may have more to do with the brain activity it silences than with the activity it creates.

Imagining as seeing in reverse

Consider how “seeing” is understood to work. Light enters the eyes and sparks neural signals. These travel through a sequence of brain regions dedicated to vision, each building on the work of the last.

The earliest regions pick out simple features such as edges and lines. The next combine those into shapes. The ones after that recognise objects, and those at the top of the sequence assemble whole faces and scenes.

Neuroscientists call this “feedforward activity” – the gradual transformation of raw light into something you can name, whether it’s a dog, a friend, or both.

In brain science, the standard view is that visual imagination is this original seeing process run in reverse, from within your mind rather than from light entering your eyes.

So, when you hold the face of a friend in mind, you start with an abstract idea of them – a memory or a name, pulled from the filing cabinet of regions that sit beyond the visual system itself.

That idea travels back down through the visual sequence into the early visual areas, which serve as your brain’s workshop where a face would normally be reconstructed from its parts – the curve of a jawline, the specific shade of an eye. These downward signals are called “feedback activity”.

A signal through the static

However, prior research shows this feedback activity doesn’t drive visual neurons to fire in the same way as when you actually see something.

At least in the brain regions early in the vision process, feedback instead modulates brain activity. This means it increases or decreases the activity of the brain cells, reshaping what those neurons are already doing.

Even behind closed eyes, early visual brain areas keep producing shifting patterns of neural activity resembling those the brain uses to process real vision.

Imagination doesn’t need to build a face from scratch. The raw material is already there. In the internal rumblings of your visual areas, fragments of every face you know are drifting through at low volume. Your friend’s face, even now, is passing through in pieces, scattered and unrecognised. What imagining does is hold still the currents that would otherwise carry those pieces away.

All that’s needed is a small, targeted suppression of neurons that are pulled by brain activity in a different direction, and your friend’s face settles out of the noise, like a signal carving its way through static.

Steering the brain

In mice, artificially switching on as few as 14 neurons in a sensory brain region is enough for the animal to notice it and lick a sugar-water spout in response. This shows how small an intervention in the brain can be while still steering behaviour.

While we don’t know how many neurons are needed to steer internal activity into a conscious experience of imagination in humans, growing evidence shows the importance of dampening neural activity.

In our earlier experiments, when people imagined something, the fingerprint it left on their behaviour matched suppression of neuronal activity – not firing. Other researchers have since found the same pattern.

Other lines of evidence strengthen our theory, too. About one in 100 people have aphantasia, which means they can’t form mental images at all. One in 30 form these images so vividly they approach the intensity of images we actually see, known as hyperphantasia.

Research has found that people with weaker mental imagery have more excitable early visual areas, where neurons fire more readily on their own. This is consistent with a visual system whose spontaneous patterns are harder to hold in shape.

Taking all this together, the spontaneous activity reshaping hypothesis – our new theory that imagination carves images out of the steady stream of ongoing brain activity – explains why imagination usually feels weaker than sight. It also explains why we rarely lose track of which is which.

Visual perception arrives with a strength and regularity the brain’s own internal patterns don’t match. Imagination works with those patterns rather than against them, reshaping what is already there into something we can almost see.

The Conversation

The authors 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. How does imagination really work in the brain? New theory upends what we knew – https://theconversation.com/how-does-imagination-really-work-in-the-brain-new-theory-upends-what-we-knew-280803

The end of oil? As fuel shocks cascade, 53 nations gather to plan a fossil fuel phaseout

Source: The Conversation – Global Perspectives – By Wesley Morgan, Research Associate, Institute for Climate Risk and Response, UNSW Sydney

Anton Petrus/Getty

US President Donald Trump is a longtime climate denier and oil industry ally, who sums up his own energy policy as “drill, baby, drill”. Yet he is doing more than almost anyone to speed up the global shift from fossil fuels to clean energy and electric vehicles (EVs).

After the US and Israel struck Iran in late February, Tehran closed the Strait of Hormuz and triggered the largest disruption of oil supply in history.

Ironically for Trump and his oil industry donors, this crisis may be an irreversible tipping point for clean energy. For years, fossil fuel advocates spruiked oil, gas and coal as “reliable” energy. That narrative has been reversed. Fossil fuels have become expensive and unreliable, while renewables are cheap, reliable and secure.

For the first time ever, more than 50 nations will gather next week in Colombia to hash out how to wind down and end their dependence on coal, oil and gas. The history-making conference was planned before the Iran war. But this year’s energy crisis has greatly raised the stakes.

The oil crisis is real

Iran’s closure of the narrow Strait of Hormuz stopped oil tankers reaching their destinations. But that wasn’t all. More than 60 gas and oil sites have been damaged in the conflict so far. Even if a durable ceasefire is reached, these impacts will reverberate for months and years to come.

Around 80% of the trapped crude oil was destined for the Asia-Pacific. Faced with dwindling supply, the region’s governments are implementing emergency measures such as sending workers home, banning government travel, rationing fuel and cutting school hours.

The problem is especially bad in the Pacific. Many island nations use diesel for power generation. In response, leaders declared a regional emergency.

Fuel import bills were already a major burden for Pacific nations, leading to efforts to switch to local renewables. Fuel bills could rise by A$933 million in Fiji (nearly three times the healthcare budget).

man standing next to banana boat in turquoise blue waters, mountains as backdrop.
Pacific nations are heavily dependent on imported diesel.
Mark Direen/Pexels, CC BY-NC-ND

Scrambling for energy

When energy supplies are disrupted, leaders have three options: find alternate supplies, reduce use or switch to alternatives. In the very short term, countries aim to shore up supply, just as Australian Prime Minister Anthony Albanese did last week in Malaysia.

Countries have also moved to reduce use. This can have lasting effects. During the Middle East oil shocks of the 1970s, oil prices tripled and then doubled again. Authorities responded by improving energy productivity to do more with less. The world’s final oil demand per capita peaked in 1979 and has never recovered.

But the real difference from half a century ago is that fossil fuel alternatives are ready for prime time. Since the 1970s, the price of solar panels has fallen 99.9%, while the cost of wind has fallen 91% since 1984. Battery prices have fallen 99% since 1991.

This means it’s now viable for many nations to switch to these alternatives.

The European Union will accelerate electrification, after its fossil fuel bill increased more than $36 billion since February. France has doubled state aid to help households switch to EVs and electrify home heating. Import-dependent South Korea gets 70% of its crude oil through the Strait of Hormuz. It now plans to double renewables capacity within four years.

Electric vehicles at the tipping point?

This year’s oil shock shows signs of creating an unplanned social tipping point – a threshold for self-propelling change beyond which systems shift from one state to another. Climate scientists warn of climate tipping points which amplify feedback and accelerate warming. But social scientists also point to positive tipping points – collective action that rapidly accelerates climate action.

The rush to EVs is a case in point. In Australia, petrol prices surged almost 50% in March, and diesel more than 70%. It’s no surprise new EV sales are at an all-time high, while secondhand EV sales more than doubled last month.

Australia’s 1.3 million hybrid and battery electric vehicles avoid almost 15 million litres of petrol and diesel use every week.

The rush to electric transport is global. Most new Chinese cars are powered by batteries, not oil. Battery electric vehicles outsold petrol cars for the first time in Europe in January.

A conference to quit fossil fuels

The routine burning of coal, oil and gas is the primary driver of the climate crisis. The world’s highest court last year made clear nations have obligations to stop burning fossil fuels.

But fossil fuels have barely been mentioned in 30 years of global climate negotiations, due in part to blocking efforts by big fossil fuel exporters and lobbyists.

Frustrated by slow progress, a coalition of nations has bypassed global climate talks to discuss how to actually phase out fossil fuels.

The first of these summits will take place next week. More than 50 nations will gather in Santa Marta, Colombia, to discuss a potential standalone treaty to manage fossil-fuel phaseout while protecting workers and financial systems.

Colombian Environment Minister Irene Vélez Torres says it comes at the “best possible moment”, as the oil crisis focuses global attention on fossil fuel dependency.

If next week’s summit produces real momentum to wean off fossil fuels amid the energy crisis, we might look back at it as a social tipping point where early adopters move in earnest – and make it easier for the rest of the world to follow.

The Conversation

Wesley Morgan is a fellow with the Climate Council of Australia

Ben Newell receives funding from the Australian Research Council.

ref. The end of oil? As fuel shocks cascade, 53 nations gather to plan a fossil fuel phaseout – https://theconversation.com/the-end-of-oil-as-fuel-shocks-cascade-53-nations-gather-to-plan-a-fossil-fuel-phaseout-280263

From Fleabag to Vladimir: why has breaking the fourth wall become so common?

Source: The Conversation – Global Perspectives – By Alex Munt, Associate Professor, Media Arts & Production, University of Technology Sydney

Netflix

In the opening moments of Vladimir, Netflix’s new erotic drama series, the protagonist M (Rachel Weisz) is sprawled on a couch in her negligee, writing in her notepad. She leans towards the camera, then stares into the lens to address you, the viewer, on your couch.

In film and television, this is called “breaking the fourth wall”. It is a ploy of metafiction: a kind of self-aware mode of storytelling.

The fourth wall is the invisible plane through which the camera observes the action. To break the fourth wall is to play with – or sever – audiences’ suspension of disbelief, and abandon the norms of screen narration.

The history of breaking the fourth wall is almost as long as the history of cinema itself. Edwin S. Porter’s film The Great Train Robbery ends with an outlaw firing his gun directly towards the camera. Back in 1903, audiences ducked for cover.

Nearly a century later, director Martin Scorsese paid homage to Porter in Goodfellas (1990) in a scene where Mobster Tommy DeVito (Jo Pesci) fires his gun directly at the screen. Here, the fourth wall break is used in an existential moment for Henry Hill (Ray Liotta) – rather than for pure shock.

In fact, the shock value of the technique has depleted over time, as audiences have become more media literate.

Making the invisible visible

The fourth wall breaks from early cinema fast disappeared with the industrialisation of the medium. The rise of the American studio system privileged some film techniques over others.

The “Classical Hollywood” style – think Casablanca (1942) – was built on a premise of invisibility, from the carefully directed eye-lines of actors, to “continuity” editing that stitched together different camera angles.

In Breathless (À bout de souffle, 1959) Jean-Luc Godard opted for jump-cuts and “direct address”. This is when a character speaks to, or looks directly at, the viewer.

Today, direct address is used widely across genres, from Barbie (2023), to Marvel’s Deadpool films (2016, 2018, 2024), and Jane Austen adaptations such as Persuasion (2022).

On television, we’ve seen women creators and characters explore the power of direct address in a re-calibration of the “male gaze”.

One example is Phoebe Waller-Bridges’ confessions to the camera in Fleabag (2016–19). Cinematographer Tony Miller notes how creative camera choices work in conjunction with direct address to make viewers “complicit in her [character’s] journey”.

The direct gaze

A fourth wall break is not always dialogue-driven. In Persona (1966) film auteur Ingmar Bergman directed his actors to stare deep into the abyss of the camera lens, delivering existential malaise.

This direct gaze has been remediated for streaming programs, including in the
intense close-up shots of Carmy (Jeremy Allen-White) in the final season of The Bear (2025), and knowing glances from the troubled Rue (Zendaya) in Euphoria (2019–26).

Fourth wall breaks can also be graphic. In Pulp Fiction, Mia Wallace (Uma Thurman) traces a square of light on the screen with her finger instead of calling Vincent Vega (John Travolta) a “square”.

And in Michael Haneke’s films Funny Games (1997, 2007) a home invader literally “rewinds” the story when a victim kills his accomplice. These kind of wall breaks call attention to the invisible membrane of the screen.

As filmmaker Mark Cousins attests in The Story of Film: An Odyssey, the medium has advanced over time through innovation and the recycling of techniques such as fourth wall breaks.

Is breaking the fourth wall back in vogue?

With the dominance of literary adaptations for the screen (and IP-driven screen stories in general) we’re likely to see more cases of direct address, as screenwriters seek to creatively refashion texts for the screen. Vladimir, for instance, is an adaptation of Julia May Jonas’ 2022 novel of the same name.

While breaking the fourth wall may have lost its shock value, it remains a bold storytelling device which, if done well, can set apart one screen production from another.

Actor Matt Damon recently pointed out how streamers such as Netflix are discussing the potential to reiterate “the plot three or four times in the dialogue” of a film, to account for people who scroll on their phone while listening to “background TV”.

Having a character speak directly to a distracted audience may be one way to return their gaze to the bigger screen.

Hyper-reality in unscripted TV

Breaking the fourth wall sits within a wider envelope of “metafictional” storytelling.

As screen culture becomes increasingly aware of its own machinery, unscripted genres such as reality TV are not merely breaking the fourth wall, but abandoning the conceit of separation entirely. The boundaries between cast, camera, story producers and audience have become increasingly porous.

Alex Baskin, executive producer of the long-running series Vanderpump Rules (2013–25), describes this as “hyperreality”. In the wake of Scandoval, the cheating scandal of Tom Sandoval, the reality TV cast started to intervene in the producers’ narrative arcs by speaking on camera about audience feedback, and providing meta commentary on their own “edits”.

When Ariana Madix (Sandoval’s ex) refused to film with him, it disrupted plans for a neat season finale based on his apology. Madix left the set, effectively ending the entire show. Fellow cast member Tom Schwartz called it a “plot twist”. Unsurprisingly, Scorsese is a fan of the show.

Meta and hyperreal storytelling will continue to be on the rise as screen creators seek to imbue a point-of-difference in a congested market – serving an ever-distracted audience.

The Conversation

Alex Munt 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. From Fleabag to Vladimir: why has breaking the fourth wall become so common? – https://theconversation.com/from-fleabag-to-vladimir-why-has-breaking-the-fourth-wall-become-so-common-280716

Why the US military is stuck using $1 million missiles against Iran’s $20,000 drones

Source: The Conversation – USA – By Aaron Brynildson, Law Instructor, University of Mississippi

A drone is seen during a suspected drone strike targeting an oil warehouse near Erbil, the capital of Iraq’s Kurdistan Region, on April 1, 2026. Gailan Haji/Middle East Images/AFP via Getty Images

It may sound hard to believe, but the almost trillion-dollar U.S. military is struggling to fight cheap drones in its war with Iran.

Iran has built a simple drone, the Shahed, with a motorcycle-type engine, loaded it with explosives and successfully targeted its neighbors’ cities and power plants.

Iran has also hit U.S. military bases with these drones, including an early April 2026 attack on the U.S. Victory Base Complex in Baghdad.

The drones cost between US$20,000 and $50,000 to build. In response, the U.S. military sometimes fires missiles worth more than $1 million to shoot one down.

As a former U.S. Air Force officer and now national security scholar, I believe that math is a problem: The U.S. military for now has a $1 million answer to a $20,000 question. This math tells you almost everything you need to know about one of America’s biggest national security headaches.

And the frustrating part is that the U.S. military watched this happen in Ukraine for years. It knew the threat was coming.

The weapon that changed modern war

The Shahed isn’t impressive because it’s high-tech. It’s impressive because it isn’t.

Inspection of captured Shahed drones has found that many of their parts are made by ordinary commercial companies. That includes processors from a U.S. manufacturer, fuel pumps from a U.K. company and converters from China.

These military components aren’t hard to get. You could find similar parts in factories or farm machinery. That’s exactly what makes the Shahed so tough to deal with.

Russia, which also produces the drone, tolerates losing more than 75% of its Shahed stock because even at those loss rates, it’s winning the math battle against Ukraine. Russia or Iran don’t need every drone to hit its target. They just need to keep sending waves of them until their opponent runs out of expensive missiles to shoot back.

Ukraine, which had no choice but to learn fast, eventually figured out a better answer. Ukraine developed cheap interceptor drones that could slam into Shahed drones before they reached their targets. Each interceptor costs about $1,000 to $2,000, and Ukrainian manufacturers are producing thousands of them per month. That’s better math: a $2,000 interceptor against a $20,000 attacker.

A fragment of a drone rests on the ground.
This undated photograph released by the Ukrainian military’s Strategic Communications Directorate shows the wreckage of what Kyiv has described as an Iranian Shahed drone downed near Kupiansk, Ukraine.
Ukrainian military’s Strategic Communications Directorate via AP

Ukraine’s battlefield experience, as a result, has become one of the most valuable resources in the world, with American and allied forces asking Ukrainian drone experts to share their knowledge.

Why can’t the U.S. churn out a solution of its own? Because the U.S. military doesn’t have a technology problem but a bureaucracy problem.

The Pentagon’s three-legged slowdown

The U.S. Department of Defense typically can’t just buy things. It follows a long, complicated process that can take a decade or more to go from “we need something” to “here it is.” That process runs through three separate bureaucratic systems, each of which can cause years of delay.

First, someone must write a formal document, known as a requirement, that explains exactly what they need and why. A military service, such as the Air Force, for example, drafts up a requirement and routes it through an internal service review within only their branch.

Until recently, this service-vetted requirement went through a Pentagon review process, the Joint Capabilities Integration and Development System, where all joint services took a look. This process, which the Department of Defense ended in 2025, required approval from military officials.

Even though the joint requirements process was ended, implementation of a new system is far from complete, and the existing culture potentially remains. Under the old requirements process, it took over 800 days to get a requirement approved.

Second, any new program then needs money. This is handled through the planning, programming, budgeting and execution process, a budget cycle designed in 1961. Getting a new program into the budget typically takes more than two years after the requirement is approved, because the military must submit its budget request years in advance. By then, the threat has potentially already moved on.

Third, once a requirement is approved and money allocated, the program then must be developed and built. The average major defense acquisition program now takes almost 12 years from program start just to deliver an initial capability to troops in the field, according to a 2025 Government Accountability Office report.

Add it up and you get a system where the military sees a threat, begs for a solution, argues for money and waits a decade.

Why the system is built this way

The Shahed drone exposed a gap that defense experts have been warning about for years: The U.S. military is very good at building the most advanced, most expensive weapons in the world, but it struggles to build cheap, simple things fast. That is the opposite of what this new kind of warfare demands.

It would be easy, but inaccurate, to blame the military for the decade-long contract process. The real answer is more complicated.

A man in a suit stands next to a drone and speaks to a group of seated people.
House Speaker Mike Johnson speaks next to an Iranian Shahed-136 drone on May 8, 2025, at the U.S. Capitol in Washington.
Tom Brenner for The Washington Post via Getty Images

The Pentagon’s lengthy process was designed by the Department of Defense and Congress for a reason. Policymakers created the current system during the Cold War to combat excessive and redundant spending by the separate service branches. The system is built with checkpoints, reviews and approvals to make sure taxpayer money isn’t wasted.

Legacy military contractors also benefit from this dysfunctional process and resist change. They have the capital and know-how to wait out the predictable and stable existing contracts, while vying for new ones. These military contractors rarely need to worry about upstart contractors because they know small companies cannot survive waiting for a decade to secure funding for their prototypes.

The problem is that those rules were built for a world where the biggest threat was another superpower’s expensive jets and missiles. It wasn’t built to fight a flying bomb made from tractor parts. This type of threat requires fast innovation from lean companies, the exact companies that struggle in the current budget process.

What’s changing

There are signs of movement. In August 2025, the Pentagon killed its old requirements process entirely and replaced it with a faster, more flexible system.

However, killing the requirements process dealt with only one leg of the three-legged monster. The 1960s-era budget process that determines how money flows remains largely intact.

The most important reforms still need Congress to act, and Congress moves slowly, too. Congress has launched studies into reforming this system numerous times, with the answers being too politically difficult to implement.

Officials are expanding the use of flexible contracting tools, such as Other Transaction Authority, that let the military skip some traditional rules to get anti-drone technology faster. Yet these flexible contracting tools still represent a small slice of the Defense budget, and their effectiveness is unclear.

Ultimately, instead of using flexible contracting tools to quickly buy new prototypes, the bureaucratically easier solution could be to buy more of the expensive, already approved missiles.

This quick fix would reload the military’s stock of interceptors with existing weapons systems, which is the source of the bad math. The math would get worse and at the same time the operational imperative to find cheaper and better solutions might disappear.

So, as the Shahed keeps flying, the most powerful military in the world is still figuring out the paperwork and looking to other countries for help.

The Conversation

Aaron Brynildson served in the U.S. Air Force from 2016-2025.

ref. Why the US military is stuck using $1 million missiles against Iran’s $20,000 drones – https://theconversation.com/why-the-us-military-is-stuck-using-1-million-missiles-against-irans-20-000-drones-281089