Author: MIL-OSI Publisher

Source: The Conversation – USA (2) – By André O. Hudson, Dean of the College of Science, Professor of Biochemistry, Rochester Institute of Technology

When most people hear the word uranium, they think of mushroom clouds, Cold War standoffs or the glowing green rods from science fiction. But uranium isn’t just fuel for apocalyptic fears. It’s also a surprisingly common element that plays a crucial role in modern energy, medicine and geopolitics.

Uranium reentered the global spotlight in June 2025, when the U.S. launched military strikes on sites in Iran believed to be housing highly enriched uranium, a move that reignited urgent conversations around nuclear proliferation. Many headlines have mentioned Iran’s 60% enrichment of uranium, but what does that really mean?

As a biochemist, I’m interested in demystifying this often misunderstood element.

What is uranium?

Uranium holds the 92nd position on the periodic table, and it is a radioactive, metallic element. Radioactivity is a natural process where some atoms – like uranium, thorium and radium – break down on their own, releasing energy.

The German chemist Martin Heinrich Klaproth initially identified uranium in 1789, and he named it after the newly discovered planet Uranus. However, its power was not unlocked until the 20th century, when scientists discovered that uranium atoms could split via a process known as nuclear fission. In fission, the nucleus of the atom splits into two or more nuclei, which releases large amounts of energy.

Uranium is found almost everywhere. It is in rocks, soil and water. There are even traces of uranium in plants and animals – albeit tiny amounts. Most of it is found in the Earth’s crust, where it is mined and concentrated to increase the amount of its most useful radioactive form, uranium-235.

The enrichment dilemma

Uranium-235 is an isotope of uranium, which is a version of an element that has the same basic identity but weighs a little more or less. Think about apples from the same tree. Some are big and some are small, but they are all apples – even though they have slightly different weights. Basically, an isotope is the same element but with a different mass.

Unprocessed uranium is mostly uranium-238. It only contains approximately 0.7% uranium-235, the isotope that allows the most nuclear fission to occur. So, the enrichment process concentrates uranium-235.

Enrichment can make uranium more useful for the development of nuclear weapons, since natural uranium doesn’t have enough uranium-235 to work well in reactors or weapons. The process usually contains three steps.

The first step is to convert the uranium into a gas, called uranium hexafluoride. In the second step, the gas gets funneled into a machine called a centrifuge that spins very fast. Because uranium-235 is a little lighter than uranium-238, it moves outward more slowly when spun, and the two isotopes separate.

It’s sort of like how a salad spinner separates water from lettuce. One spin doesn’t make much of a difference, so the gas is spun through many centrifuges in a row until the uranium-235 is concentrated.

Uranium can typically power nuclear plants and generate electricity when it is 3%-5% enriched, meaning 3%-5% of the uranium is uranium-235. At 20% enriched, uranium-235 is considered highly enriched uranium, and 90% or higher is known as weapons-grade uranium.

This high grade works in nuclear weapons because it can sustain a fast, uncontrolled chain reaction, which releases a large amount of energy compared with the other isotopes.

Uranium’s varied powers

While many headlines focus on uranium’s military potential, this element also plays a vital role in modern life. At low enrichment levels, uranium powers nearly 10% of the world’s electricity.

In the U.S., many nuclear power plants run on uranium fuel, producing carbon-free energy. In addition, some cancer therapies and diagnostic imaging technologies harness uranium to treat diseases.

In naval technology, nuclear-powered submarines and aircraft carriers rely on enriched uranium to operate silently and efficiently for years.

Uranium is a story of duality. It is a mineral pulled from ancient rocks that can light up a city or wipe one off the map. It’s not just a relic of the Cold War or science fiction. It’s real, it’s powerful, and it’s shaping our world – from global conflicts to cancer clinics, from the energy grid to international diplomacy.

In the end, the real power is not just in the energy released from the element. It is in how people choose to use it.

André O. Hudson receives funding from the National Institutes of Health.

– ref. Uranium enrichment: A chemist explains how the surprisingly common element is processed to power reactors and weapons – https://theconversation.com/uranium-enrichment-a-chemist-explains-how-the-surprisingly-common-element-is-processed-to-power-reactors-and-weapons-259646

Source: The Conversation – USA (2) – By Toshi Hirabayashi, Associate Professor of Aerospace Engineering, Georgia Institute of Technology

I was preparing for my early morning class back in January 2025 when I received a notice regarding an asteroid called 2024 YR4. It said the probability it could hit Earth was unusually high.

As defending Earth from unexpected intruders such as asteroids is part of my expertise, I immediately started receiving questions from my students and colleagues about what was happening.

When scientists spot an asteroid whose trajectory might take it close to Earth, they monitor it frequently and calculate the probability that it might collide with our planet. As they receive more observational data, they get a better picture of what could happen.

Just having more data points early doesn’t make scientists’ predictions better. They need to keep following the asteroid as it moves through space to better understand its trajectory.

Reflecting on the incident a few months later, I wondered whether there might have been a better way for scientists to communicate about the risk with the public. We got accurate information, but as the questions I heard indicated, it wasn’t always enough to understand what it actually means.

Numbers change every day

The 2024 YR24 asteroid has a diameter of about 196 feet (60 meters) – equivalent to approximately a 15-story building in length.

At the time of the announcement in January, the asteroid’s impact probability was reported to exceed 1%. The impact probability describes how likely a hazardous asteroid is to hit Earth. For example, if the impact probability is 1%, it means that in 1 of 100 cases, it hits Earth. One in 100 is kind of rare, but still too close for comfort if you’re talking about the odds of a collision that could devastate Earth.

Over time, though, further observations and analyses revealed an almost-zero chance of this asteroid colliding with Earth.

After the initial notice in January, the impact probability continuously increased up to 3.1% on Feb. 18, but dropped to 1.5% on Feb. 19. Then, the impact probability continuously went down, until it hit 0.004% on Feb. 24. As of June 15, it now has an impact probability of less than 0.0000081%.

But while the probability of hitting Earth went down, the probability of the asteroid hitting the Moon started increasing. It went up to 1.7% on Feb. 24. As of April 2, it is 3.8%.

If it hits the Moon, some ejected materials from this collision could reach the Earth. However, these materials would burn away when they enter the Earth’s thick atmosphere.

Impact probability

To see whether an approaching object could hit Earth, researchers find out what an asteroid’s orbit looks like using a technique called astrometry. This technique can accurately determine an object’s orbit, down to only a few kilometers of uncertainty. But astrometry needs accurate observational data taken for a long time.

Any uncertainty in the calculation of the object’s orbit causes variations in the predicted solution. Instead of one precise orbit, the calculation usually gives scientists a cloud of its possible orbits. The ellipse enclosing these locations is called an error ellipse.

The impact probability describes how many orbital predictions in this ellipse hit the Earth.

Without enough observational data, the orbital uncertainty is high, so the ellipse tends to be large. In a large ellipse, there’s a higher chance that the ellipse “accidentally” includes Earth – even if the center is off the planet. So, even if an asteroid ultimately won’t hit Earth, its error ellipse might still include the planet before scientists collect enough data to narrow down the uncertainty.

As the level of uncertainty goes down, the ellipse shrinks. So, when Earth is inside a small error ellipse, the impact probability may become higher than when it’s inside a large error ellipse. Once the error ellipse shrinks enough that it no longer includes Earth, the impact probability goes down significantly. That’s what happened to 2024 YR4.

The impact probability is a single, practical value offering meaningful insight into an impact threat. However, just using the impact probability without any context may not provide meaningful guidelines to the public, as we saw with 2024 YR4.

Holding on and waiting for more data to refine a collision prediction, or introducing new metrics for assessing impacts on Earth, are alternative courses of action to provide people with better guidelines for future threats before adding confusion and fear.

I have been studying planetary defense, particularly being part of past, ongoing, and future small body missions. I was part of the NASA/DART mission. I am currently part of the NASA/Lucy mission and the ESA/Hera mission. I am also on the Hayabusa2# team, led by the Japanese Aerospace Exploration Agency (JAXA), as part of an international collaboration. I have no affiliation with JAXA.

– ref. How do scientists calculate the probability that an asteroid could hit Earth? – https://theconversation.com/how-do-scientists-calculate-the-probability-that-an-asteroid-could-hit-earth-249834

Source: The Conversation – USA (2) – By John Peterson, Assoc. Professor of Physics and Astronomy, Purdue University

Professional astronomers don’t make discoveries by looking through an eyepiece like you might with a backyard telescope. Instead, they collect digital images in massive cameras attached to large telescopes.

Just as you might have an endless library of digital photos stored in your cellphone, many astronomers collect more photos than they would ever have the time to look at. Instead, astronomers like me look at some of the images, then build algorithms and later use computers to combine and analyze the rest.

But how can we know that the algorithms we write will work, when we don’t even have time to look at all the images? We can practice on some of the images, but one new way to build the best algorithms is to simulate some fake images as accurately as possible.

With fake images, we can customize the exact properties of the objects in the image. That way, we can see if the algorithms we’re training can uncover those properties correctly.

My research group and collaborators have found that the best way to create fake but realistic astronomical images is to painstakingly simulate light and its interaction with everything it encounters. Light is composed of particles called photons, and we can simulate each photon. We wrote a publicly available code to do this called the photon simulator, or PhoSim.

The goal of the PhoSim project is to create realistic fake images that help us understand where distortions in images from real telescopes come from. The fake images help us train programs that sort through images from real telescopes. And the results from studies using PhoSim can also help astronomers correct distortions and defects in their real telescope images.

The data deluge

But first, why is there so much astronomy data in the first place? This is primarily due to the rise of dedicated survey telescopes. A survey telescope maps out a region on the sky rather than just pointing at specific objects.

These observatories all have a large collecting area, a large field of view and a dedicated survey mode to collect as much light over a period of time as possible. Major surveys from the past two decades include the SDSS, Kepler, Blanco-DECam, Subaru HSC, TESS, ZTF and Euclid.

The Vera Rubin Observatory in Chile has recently finished construction and will soon join those. Its survey begins soon after its official “first look” event on June 23, 2025. It will have a particularly strong set of survey capabilities.

The Rubin observatory can look at a region of the sky all at once that is several times larger than the full Moon, and it can survey the entire southern celestial hemisphere every few nights.

A survey can shed light on practically every topic in astronomy.

Some of the ambitious research questions include: making measurements about dark matter and dark energy, mapping the Milky Way’s distribution of stars, finding asteroids in the solar system, building a three-dimensional map of galaxies in the universe, finding new planets outside the solar system and tracking millions of objects that change over time, including supernovas.

All of these surveys create a massive data deluge. They generate tens of terabytes every night – that’s millions to billions of pixels collected in seconds. In the extreme case of the Rubin observatory, if you spent all day long looking at images equivalent to the size of a 4K television screen for about one second each, you’d be looking at them 25 times too slow and you’d never keep up.

At this rate, no individual human could ever look at all the images. But automated programs can process the data.

Astronomers don’t just survey an astronomical object like a planet, galaxy or supernova once, either. Often we measure the same object’s size, shape, brightness and position in many different ways under many different conditions.

But more measurements do come with more complications. For example, measurements taken under certain weather conditions or on one part of the camera may disagree with others at different locations or under different conditions. Astronomers can correct these errors – called systematics – with careful calibration or algorithms, but only if we understand the reason for the inconsistency between different measurements. That’s where PhoSim comes in. Once corrected, we can use all the images and make more detailed measurements.

Simulations: One photon at a time

To understand the origin of these systematics, we built PhoSim, which can simulate the propagation of light particles – photons – through the Earth’s atmosphere and then into the telescope and camera.

PhoSim simulates the atmosphere, including air turbulence, as well as distortions from the shape of the telescope’s mirrors and the electrical properties of the sensors. The photons are propagated using a variety of physics that predict what photons do when they encounter the air and the telescope’s mirrors and lenses.

The simulation ends by collecting electrons that have been ejected by photons into a grid of pixels, to make an image.

Representing the light as trillions of photons is computationally efficient and an application of the Monte Carlo method, which uses random sampling. Researchers used PhoSim to verify some aspects of the Rubin observatory’s design and estimate how its images would look.

The results are complex, but so far we’ve connected the variation in temperature across telescope mirrors directly to astigmatism – angular blurring – in the images. We’ve also studied how high-altitude turbulence in the atmosphere that can disturb light on its way to the telescope shifts the positions of stars and galaxies in the image and causes blurring patterns that correlate with the wind. We’ve demonstrated how the electric fields in telescope sensors – which are intended to be vertical – can get distorted and warp the images.

Researchers can use these new results to correct their measurements and better take advantage of all the data that telescopes collect.

Traditionally, astronomical analyses haven’t worried about this level of detail, but the meticulous measurements with the current and future surveys will have to. Astronomers can make the most out of this deluge of data by using simulations to achieve a deeper level of understanding.

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

– ref. Astronomy has a major data problem – simulating realistic images of the sky can help train algorithms – https://theconversation.com/astronomy-has-a-major-data-problem-simulating-realistic-images-of-the-sky-can-help-train-algorithms-258786

Source: The Conversation – USA (2) – By Stephen L. Levy, Associate Professor of Physics and Applied Physics and Astronomy, Binghamton University, State University of New York

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

How do atoms form? – Joshua, age 7, Shoreview, Minnesota

Richard Feynman, a famous theoretical physicist who won the Nobel Prize, said that if he could pass on only one piece of scientific information to future generations, it would be that all things are made of atoms.

Understanding how atoms form is a fundamental and important question, since they make up everything with mass.

The question of where atoms come from requires a lot of physics to be answered completely – and even then, physicists like me only have good guesses to explain how some atoms are formed.

What is an atom?

An atom consists of a heavy center, called the nucleus, made of particles called protons and neutrons. An atom has lighter particles called electrons that you can think of as orbiting around the nucleus.

The electrons each carry one unit of negative charge, the protons each carry one unit of positive charge, and the neutrons have no charge. An atom has the same number of protons as electrons, so it is neutral − it has no overall charge.

Now, most of the atoms in the universe are the two simplest kinds: hydrogen, which has one proton, zero neutrons and one electron; and helium, which has two protons, two neutrons and two electrons. Of course, on Earth there are lots of atoms besides these that are just as common, such as carbon and oxygen, but I’ll talk about those soon.

An element is what scientists call a group of atoms that are all the same, because they all have the same number of protons.

When did the first atoms form?

Most of the universe’s hydrogen and helium atoms formed around 400,000 years after the Big Bang, which is the name for when scientists think the universe began, about 14 billion years ago.

Why did they form at that time? Astronomers know from observing distant exploding stars that the size of the universe has been getting bigger since the Big Bang. When the hydrogen and helium atoms first formed, the universe was about 1,000 times smaller than it is now.

And based on their understanding of physics, scientists believe that the universe was much hotter when it was smaller.

Before this time, the electrons had too much energy to settle into orbits around the hydrogen and helium nuclei. So, the hydrogen and helium atoms could form only once the universe cooled down to something like 5,000 degrees Fahrenheit (2,760 degrees Celsius). For historical reasons, this process is misleadingly called recombination − combination would be more descriptive.

The helium and deuterium − a heavier form of hydrogen − nuclei formed even earlier, just a few minutes after the Big Bang, when the temperature was above 1 billion F (556 million C). Protons and neutrons can collide and form nuclei like these only at very high temperatures.

Scientists believe that almost all the ordinary matter in the universe is made of about 90% hydrogen atoms and 8% helium atoms.

How do more massive atoms form?

So, the hydrogen and helium atoms formed during recombination, when the cooler temperature allowed electrons to fall into orbits. But you, I and almost everything on Earth is made of many more massive atoms than just hydrogen and helium. How were these atoms made?

The surprising answer is that more massive atoms are made in stars. To make atoms with several protons and neutrons stuck together in the nucleus requires the type of high-energy collisions that occur in very hot places. The energy needed to form a heavier nucleus needs to be large enough to overcome the repulsive electric force that positive charges, like two protons, feel with each other.

Protons and neutrons also have another property – kind of like a different type of charge – that is strong enough to bind them together once they are able to get very close together. This property is called the strong force, and the process that sticks these particles together is called fusion.

Scientists believe that most of the elements from carbon up to iron are fused in stars heavier than our Sun, where the temperature can exceed 1 billion F (556 million C) – the same temperature that the universe was when it was just a few minutes old.

But even in hot stars, elements heavier than iron and nickel won’t form. These require extra energy, because the heavier elements can more easily break into pieces.

In a dramatic event called a supernova, the inner core of a heavy star suddenly collapses after it runs out of fuel to burn. During the powerful explosion this collapse triggers, elements that are heavier than iron can form and get ejected out into the universe.

Astronomers are still figuring out the details of other fantastic stellar events that form larger atoms. For example, colliding neutron stars can release enormous amounts of energy – and elements such as gold – on their way to forming black holes.

Understanding how atoms are made just requires learning a little general relativity, plus some nuclear, particle and atomic physics. But to complicate matters, there is other stuff in the universe that doesn’t appear to be made from normal atoms at all, called dark matter. Scientists are investigating what dark matter is and how it might form.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Stephen L. Levy receives funding from the National Science Foundation and the National Institutes of Health. He is affiliated with CyteQuest, Inc.

– ref. How do atoms form? A physicist explains where the atoms that make up everything around come from – https://theconversation.com/how-do-atoms-form-a-physicist-explains-where-the-atoms-that-make-up-everything-around-come-from-256172

Source: The Conversation – USA (2) – By Arindam Sau, Ph.D. Candidate in Chemistry, University of Colorado Boulder

Manufactured chemicals and materials are necessary for practically every aspect of daily life, from life-saving pharmaceuticals to plastics, fuels and fertilizers. Yet manufacturing these important chemicals comes at a steep energy cost.

Many of these industrial chemicals are derived primarily from fossil fuel-based materials. These compounds are typically very stable, making it difficult to transform them into useful products without applying harsh and energy-demanding reaction conditions.

As a result, transforming these stubborn materials contributes significantly to the world’s overall energy use. In 2022, the industrial sector consumed 37% of the world’s total energy, with the chemical industry responsible for approximately 12% of that demand.

Conventional chemical manufacturing processes use heat to generate the energy needed for reactions that take place at high temperatures and pressures. An approach that uses light instead of heat could lower energy demands and allow reactions to be run under gentler conditions — like at room temperature instead of extreme heat.

Sunlight represents one of the most abundant yet underutilized energy sources on Earth. In nature, this energy is captured through photosynthesis, where plants convert light into chemical energy. Inspired by this process, our team of chemists at the Center for Sustainable Photoredox Catalysis, a research center funded by the National Science Foundation, has been working on a system that uses light to power reactions commonly used in the chemical manufacturing industry. We published our results in the journal Science in June 2025.

We hope that this method could provide a more economical route for creating industrial chemicals out of fossil fuels. At the same time, since it doesn’t rely on super-high temperatures or pressures, the process is safer, with fewer chances for accidents.

How does our system work?

The photoredox catalyst system that our team has developed is powered by simple LEDs, and it operates efficiently at room temperature.

At the core of our system is an organic photoredox catalyst: a specialized molecule that we know accelerates chemical reactions when exposed to light, without being consumed in the process.

Much like how plants rely on pigments to harvest sunlight for photosynthesis, our photoredox catalyst absorbs multiple particles of light, called photons, in a sequence.

These photons provide bursts of energy, which the catalyst stores and then uses to kick-start reactions. This “multi-photon” harvesting builds up enough energy to force very stubborn molecules into undergoing reactions that would otherwise need highly reactive metals. Once the reaction is complete, the photocatalyst resets itself, ready to harvest more light and keep the process going without creating extra waste.

Designing molecules that can absorb multiple photons and react with stubborn molecules is tough. One big challenge is that after a molecule absorbs a photon, it only has a tiny window of time before that energy fades away or gets lost. Plus, making sure the molecule uses that energy the right way is not easy. The good news is we’ve found that our catalyst can do this efficiently at room temperature.

Enabling greener chemical manufacturing

Our work points toward a future where chemicals are made using light instead of heat. For example, our catalyst can turn benzene — a simple component of crude oil — into a form called cyclohexadienes. This is a key step in making the building blocks for nylon. Improving this part of the process could reduce the carbon footprint of nylon production.

Imagine manufacturers using LED reactors or even sunlight to power the production of essential chemicals. LEDs still use electricity, but they need far less energy compared with the traditional heating methods used in chemical manufacturing. As we scale things up, we’re also figuring out ways to harness sunlight directly, making the entire process even more sustainable and energy-efficient.

Right now, we’re using our photoredox catalysts successfully in small lab experiments — producing just milligrams at a time. But to move into commercial manufacturing, we’ll need to show that these catalysts can also work efficiently at a much larger scale, making kilograms or even tons of product. Testing them in these bigger reactions will ensure that they’re reliable and cost-effective enough for real-world chemical manufacturing.

Similarly, scaling up this process would require large-scale reactors that use light efficiently. Building those will first require designing new types of reactors that let light reach deeper inside. They’ll need to be more transparent or built differently so the light can easily get to all parts of the reaction.

Our team plans to keep developing new light-driven techniques inspired by nature’s efficiency. Sunlight is a plentiful resource, and by finding better ways to tap into it, we hope to make it easier and cleaner to produce the chemicals and materials that modern life depends on.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Light-powered reactions could make the chemical manufacturing industry more energy-efficient – https://theconversation.com/light-powered-reactions-could-make-the-chemical-manufacturing-industry-more-energy-efficient-257796

Source: The Conversation – USA (2) – By Andrea Stanton, Associate Professor of Islamic Studies & Faculty Affiliate, Center for Middle East Studies, University of Denver

After 12 days of trading deadly airstrikes, Israel and Iran confirmed on June 24, 2025, that a ceasefire is in effect, one day after President Donald Trump proclaimed the countries reached a deal to end fighting. Experts are wondering how long the ceasefire, which does not contain any specific conditions, will hold.

Meanwhile, Republicans and Democrats alike have debated whether the Trump administration’s decision to bomb Iran’s three nuclear facilities on June 22 constituted an unofficial declaration of war – since Trump has not asked Congress to formally declare war against Iran.

The United States’ involvement in the fighting between Iran and Israel, which Israel started on June 12, has also sparked concerned comparisons with the eight-year war the U.S. waged in Iraq, another Middle Eastern country.

The U.S. invaded Iraq more than 20 years ago in March 2003, claiming it had to disarm the Iraqi government of weapons of mass destruction and end the dictatorial rule of President Saddam Hussein. U.S. soldiers captured Saddam in December 2003, but the war dragged on through 2011.

A 15-month search by U.S. and United Nations inspectors revealed in 2004 that Iraq had no weapons of mass destruction to seize.

The Trump administration, bolstered by the Israeli government, has claimed that Iran’s development of nuclear weapons represents an imminent, dangerous threat to Western countries and the rest of the world. Iran says that its nuclear development program is for civilian use. While the International Atomic Energy Agency, an independent organization that is part of the United Nations, monitors Iran and other countries’ nuclear development work, Iran has not complied with recent IAEA requests for information about its nuclear program.

Trump has also called for regime change in Iran, writing on his Truth Social media platform on June 22 that he wants to “Make Iran Great Again”, though he has since walked back that plan. The case of U.S. involvement in Iraq might offer some lessons in this current moment.

The start and cost of the Iraq War

The conflict between Western powers and Iraq dragged on until 2011. More than 4,600 American soldiers died in combat – and thousands more died by suicide after they returned home.

More than 288,000 Iraqis, including fighters and civilians, have died from war-related violence since the invasion.

The war cost the U.S. over $2 trillion.

And Iraq is still dealing with widespread political violence between rival religious-political groups and an unstable government.

Most of these problems stem directly or indirectly from the war. The 2003 U.S. invasion of Iraq and the war that followed are defining events in the histories of both countries – and the region. Yet, for many young people in the United States, drawing a connection between the war and its present-day impact is becoming more difficult. For them, the war is an artifact of the past.

I am a Middle East historian and an Islamic studies scholar who teaches two undergraduate courses that cover the 2003 invasion and the Iraq War. My courses attract students who hope to work in politics, law, government and nonprofit groups, and whose personal backgrounds include a range of religious traditions, immigration histories and racial identities.

The stories of the invasion and subsequent war resonate with them in the same way that stories of other past events do – they’re eager to learn from them, but don’t see them as directly connected to their lives.

A generational shift

Since I started teaching courses related to the Iraq War in 2010, my students have shifted from millennials to Generation Z. The latter were born between the mid-1990s and early 2010s. There has also been a change in how these students understand major early 21st-century events, including the U.S. invasion of Iraq.

I teach this event by showing things like former President George W. Bush’s March 19, 2003, televised announcement of the invasion.

I also teach it through the flow of my lived experience. That includes remembering the Feb. 15, 2003, anti-war protests that took place in over 600 cities around the world as an effort to prevent what appeared to be an inevitable war. And I show students aspects of material culture, like the “Iraqi most wanted” deck of playing cards, distributed to deployed U.S. military personnel in Iraq, who used the cards for games and to help them identify key figures in the Iraq government.

The millennial students I taught around 2010 recalled the U.S. invasion of Iraq from their early teen years – a confusing but foundational moment in their personal timelines.

But for the Gen-Z students I teach today, the invasion sits firmly in the past, as a part of history.

Why this matters

Since the mid-2010s, I have not been able to expect students to enroll in my course with personal prior knowledge about the invasion and war that followed. In 2013, my students would tell me that their childhoods had been defined by a United States at war – even if those wars happened far from U.S. soil.

Millennial students considered the trifecta of 9/11, the war in Afghanistan and the war in Iraq to be defining events in their lives. The U.S. and its allies launched airstrikes against al-Qaida and Taliban targets in Afghanistan on Oct. 7, 2001, less than a month after the Sept. 11 terrorist attacks. This followed the Taliban refusing to hand over Osama bin Laden, the architect of 9/11.

By 2021, my students considered Bush’s actions with the same level of abstract curiosity that they had brought to the class’s earlier examination of the 1957 Eisenhower Doctrine, which said that a country could request help from U.S. military forces if it was being threatened by another country, and was used to justify U.S. military involvement in Lebanon in 1958.

On an educational level, this means that I now provide much more background information on the first the Gulf War, the 2000 presidential elections, the Bush presidency, the immediate U.S. responses to 9/11 and the Afghanistan invasion than I had to do before. All of these events help students better understand why the U.S. invaded Iraq and why Americans felt so strongly about the military action – whether they were for or against the invasion.

The Iraq invasion lost popularity among Americans within two years. In March 2003, 71% of Americans said that the U.S. made the right decision to use military force in Iraq.

That percentage dropped to 47% in 2005, following the revelation that there were no weapons of mass destruction. Yet those supporters continued to strongly endorse the invasion in later polls.

In 2018, just over half of Americans believed that the U.S. failed to achieve its goals, however those goals might have been defined in Iraq.

A new set of priorities

Older Americans age 65 and up are more likely than young people to prioritize foreign policy issues, including maintaining a U.S. military advantage.

Younger Americans – age 18 to 39 – say the top issues that require urgency are providing support to refugees and limiting U.S. military commitments abroad, according to a 2021 Pew research survey.

Generation Z members are also less likely than older Americans to think that the U.S. should act by itself in defending or protecting democracy around the world, according to a 2019 poll by the think tank Center for American Progress.

They also agree with the statement that the United States’ “wars in the Middle East and Afghanistan were a waste of time, lives, and taxpayer money and they did nothing to make us safer at home.” They prefer that the U.S. use economic and diplomatic means, rather than military intervention, to advance American interests around the world.

Israel’s conflict with Iran may not flare again and give way to more airstrikes and violence. If the countries resume fighting, however, their conflict threatens to draw in Lebanon, Qatar and other countries in the Middle East, as well as likely the U.S. – and to drag on for a long time.

This is an update from a story originally published on March 15, 2023.

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

– ref. Israel-Iran war recalls the 2003 US invasion of Iraq – a war my undergraduate students see as a relic of the past – https://theconversation.com/israel-iran-war-recalls-the-2003-us-invasion-of-iraq-a-war-my-undergraduate-students-see-as-a-relic-of-the-past-259652

Source: The Conversation – USA (2) – By Gregory F. Treverton, Professor of Practice in International Relations, USC Dornsife College of Letters, Arts and Sciences

The Trump administration’s decision to bomb Iran dramatically marks the now nearly half-century of hostility between the United States and Iran, which began in 1979 with Iran’s takeover of the U.S. Embassy in Tehran and the taking of 52 diplomatic hostages.

It remains uncertain whether the Iran-Israel ceasefire will hold, given President Donald Trump’s seemingly impulsive policy decisions and an Israeli leader who critics say pursues war to stay in power.

Additional unpredictability can be seen in a weakened Iran government that is unpopular with its own people but must also bet that standing up to the U.S. and Israel will induce its people to rally around the flag, even if they don’t like who holds that flag.

As a U.S. international relations scholar, I think whatever comes next will be well informed by what has already happened in U.S.-Iran history. That includes an offer from Trump – who considers himself the consummate negotiator – to Iran to return to the negotiating table.

The shah’s last visit to Washington

The opening bracket in modern U.S.-Iran relations was the 1979 Islamic Revolution that overthrew Shah Mohammad Reza Pahlavi,“ whom a CIA covert action had restored to leadership a quarter-century earlier.

As a young National Security Council staffer, I stood on the South Lawn of the White House as the shah’s helicopter landed in 1977 for a state visit to his close ally, the United States.

The episode was perhaps a metaphor for the two countries’ relationship. I stood next to a colleague who had written for President Jimmy Carter remarks that included fulsome praise of the shah, but his crack to me was: “You’ll recognize the shah. He’s the one with blood under his fingernails.” Beneath a formal alliance, there was a good deal of cynicism on the U.S. part about the shah’s repressive regime and use of secret police to suppress opposition.

Pro- and anti-shah protesters were demonstrating at the bottom of the Ellipse, the park south of the White House grounds. The U.S. Park Police, understandably but unwisely, sought to separate them with tear gas, which then wafted over the proceedings on the South Lawn.

The impact of the hostage crisis

It’s impossible to overstate the effect of the 1979 hostage crisis, when Iranian students seized the U.S. Embassy in Tehran, holding 62 American hostages for 444 days.

The Carter administration negotiated the Algiers Accords, which led to the release of the hostages in January 1981. There have been persistent accounts, none ever fully validated, that the incoming Reagan administration dealt with Iran to delay the release until after the new president’s inauguration.

The crisis not only cost Carter his job, but it also cast an enduring shadow over the U.S.-Iran relationship, compounding Americans’ difficulty in understanding a regime that was not only theocratic but Muslim.

The 1980s witnessed a whipsaw of relations.

From 1980 to 1988, as Iran and Iraq fought a bloody war to a stalemate, the U.S. saw the power of both countries contained, but it did provide intelligence and logistical support to Iraq.

Then came the Iran-Contra Affair of 1985 to 1987. It was the Reagan administration’s most serious scandal, in which White House officials illegally sold sanctioned arms to Iran and secretly diverted the proceeds to the Nicaraguan Contras. In a moment straight out of comic opera, National Security Council aides brought a goodwill chocolate cake to Tehran during a secret diplomatic mission in May 1986.

In 1988, a U.S. ship struck an Iranian mine in the Persian Gulf. The U.S. retaliated by destroying oil platforms and damaging Iranian ships in “Operation Praying Mantis,” and tragically – and mistakenly – shot down Iran Air Flight 655, killing 290 civilians.

The 1990s and 2000s again displayed the limits of the relationship.

In 1995, President Bill Clinton imposed an oil and trade embargo against Iran, and Congress passed the Iran–Libya Sanctions Act in 1996, which imposed economic sanctions on companies doing business with Iran and Libya.

In 1998, Iranian President Mohammad Khatami called for a “dialogue of civilizations,” prompting cautious U.S. signals of engagement.

Then, in 2002, President George W. Bush labeled Iran part of the “axis of evil,” a sharp rhetorical escalation. For its part, Iran alleged U.S. drone incursions and covert operations. Limited diplomatic back channels emerged, but to no outcome.

In 2009, President Barack Obama reached out to Tehran amid post-election unrest in Iran, but two years later Iran threatened to close the Strait of Hormuz, a crucial route for oil shipments to the West.

In 2015, the two countries were party to the Joint Comprehensive Plan of Action, with Iran agreeing to limit its nuclear program under international oversight.

Two years later, though, President Trump withdrew from the nuclear deal and reimposed sweeping sanctions in a “maximum pressure” campaign.

In 2019 and 2020, a series of tit-for-tat escalations culminated in the Jan. 3, 2020, U.S. drone strike that assassinated senior Iranian General Qassem Soleimani. Iran retaliated with missile strikes on U.S. bases in the region.

U.S. sanctions continued in the Biden administration as Iran pursued deeper ties with Russia, China and nonstate proxies, especially Hezbollah in Lebanon and the Houthis in Yemen.

What lessons?

What can be learned from this tangled history?

First, that negotiations are possible between the two countries, but they are neither easy nor likely to produce more than limited outcomes. Indeed, high-level indirect talks mediated by Oman began in April 2025, though they were in suspension when the U.S. bombers struck.

Second, despite the Iran regime’s unpopularity, regime change in Iran is unlikely. Assassinating Ayatollah Ali Khameini would likely abet the “rally ‘round the flag” effect, as did the assassination of Soleimani.

Third, Iran has been careful in its responses even to Israeli aggression but especially in engaging the U.S. in military conflict, a caution the American B-2 bombings on June 21 can only underscore.

Iran had to retaliate, so the attack on the U.S. base in Qatar came as no surprise. But Iran was careful in retaliating, even notifying the U.S. in advance.

The dropping of U.S. bombs, followed by Iran’s careful retaliation, was the opportunity for Trump to make an offer Iran couldn’t refuse.

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

– ref. What happens next in US-Iran relations will be informed by the two countries’ shared history – https://theconversation.com/what-happens-next-in-us-iran-relations-will-be-informed-by-the-two-countries-shared-history-259607