Does International Law Make A Difference? This is the question I've grappled with throughout my career. Read my wide-ranging conversation with the co-editors-in-chief of the Yale Journal of International Law. yjil.yale.edu/posts/2026-0...

It's time for Congress to step up. It should start by cutting off funding for this war until Congress authorizes it. Then it needs to reform the War Powers Act to do the same for all future conflicts so that we don't find ourselves right back here again. www.stripes.com/theaters/us/...

The Defense Department has requested funds for danger pay to troops that are at increased risk of taking hostile fire or other dangers. Rather than paying more danger pay, let's stop the illegal war of choice that's putting our troops in danger. www.militarytimes.com/news/your-mi...

As the death toll reaches 190, it's time for another reminder that the boat strikes are unlawful under both international and domestic law--and they are a stain on our national conscience. For much more, take a look at this @justsecurity.org collection: www.justsecurity.org/120753/colle...

Trump sends US warships into the Persian Gulf to escort trapped ships out of the Strait of Hormuz, potentially making a dangerous situation even more dangerous. Featuring @oonahathaway.bsky.social, Professor of International Law at Yale Law School. soundcloud.com/user-8304426...

This is what ongoing hostilities looks like. But to be clear, the blockade & state of military confrontation were enough to constitute continuing "hostilities" under the WPR 60-day clock before the latest skirmish, as @oonahathaway.bsky.social and I explained👇 www.justsecurity.org/137669/60-da...

1/ NEW: The Trump administration's new notification to Congress attempting to get out from under the War Powers Resolution 60-day clock for its #Iran war is utterly unconvincing, and also breaks new ground in a few interesting ways:

Today, Trump "will take a war that is already doubly illegal and turn it into a triply-illegal war. He will also make it clear, if it was not already, that he regards the law as no constraint on his use of the U.S. military’s lethal power." Read more here: www.justsecurity.org/137669/60-da...

The war in Iran becomes triply illegal today. Read more from me and @tessbridgeman.bsky.social:

Civilians harmed in war are nearly always left to pick up the pieces alone. With @oonahathaway.bsky.social and @sarahdonilon.bsky.social, we propose a comprehensive scheme for compensating them, building on longstanding U.S. programs for other civilians we put in harm's way. Check it out:

With the War Powers Resolution's (WPR) 60-day clock running out for the #Iran war, let's clear up a few things: 1) The deadline for #Trump to get authorization from Congress was *before* he went to war. That is required by the Constitution, which gives that power to Congress, not the President.

What do states owe the innocent civilians they kill in war? When we started this article, we had no idea how relevant it would be when it was published. "War Hazards Compensation for Civilians"--now out! With coauthors @sarahdonilon.bsky.social & Carter Squires. papers.ssrn.com/sol3/papers....

Congratulations to the new members of the @ajil.bsky.social board! @dianemarieamann.bsky.social and @tomdannenbaum.bsky.social are outstanding scholars and will bring their expertise to AJIL, the flagship publication of @asilorg.bsky.social and the leading international law journal in the world.

This piece @scottjshapiro.bsky.social and I wrote in 2020 suddenly seems very timely. You can read it here: authory.com/app/content/... or here: foreignpolicy.com/2020/07/04/a...

It seems trivial, but this move to rename the Department of Defense the Department of War (at a cost of $50-$100 million) symbolizes Trump's broader rejection of the postwar legal order, grounded in the prohibition on the use of force. Congress must vote no. www.militarytimes.com/news/pentago...

New article! "Queering the Crime of Persecution," with Samantha Kiernan, in SJIL. It explains the distinct harm caused by persecution based on real or perceived sexual orientation or gender identity and the importance of recognizing it as a crime of persecution. papers.ssrn.com/sol3/papers....

I am honored to assume the presidency of @asilorg.bsky.social. Our 4000 members share a mission: to foster the study of international law, and to promote the establishment and maintenance of international relations on the basis of law and justice. www.justsecurity.org/137021/remar...

I enjoyed this conversation about international law and why and how it matters—today more than ever. Take a listen:

I guess that's me. (Interesting to see my tweets turned into a "story.") www.msn.com/en-us/news/p...

The War in Iran is maybe over, maybe not, but what happens next? What happens to the US after we blew through international agreements, US law, alienated our allies, and set an example for our adversaries? @oonahathaway.bsky.social joins me on Make It Make Sense to talk about it all.

Great conversation about the Iran war and the many legal issues it raises. Take a listen: podcasts.apple.com/us/podcast/m...

Excited to see the Spanish edition of "The Internationalists" now out! LOS INTERNACIONALISTAS: UN PLAN REVOLUCIONARIO QUE PROSCRIBIÓ LA GUERRA Y REINVENTÓ EL MUNDO: 21 (BIBLIOTECA DE LITERATURA Y DERECHOS HUMANOS BERG INSTITUTE) www.amazon.es/-/en/LOS-INT...

Yale Law School Prof. @oonahathaway.bsky.social said in Feb. the Supreme Court has become "extremely partisan in a way that we haven't seen... in my lifetime." "Big question is, are they going to apply the same limitations to President Trump that they applied to President Biden?" bit.ly/4vdQmN0

On Saturday, a U.S. boat strike killed another five people, leaving one survivor, bringing the number of people who have been killed in illegal boat strikes by the U.S. military to at least 168 since the Trump administration began targeting boats in early September. apnews.com/article/boat...

"It's absolutely critical that young people turn out to vote, express themselves, and play their role in our constitutional democracy, because it won't work if they don't," says @yalelawschool-yls.bsky.social Professor @oonahathaway.bsky.social. Follow on Apple: bit.ly/4vdQmN0

As President Trump launches illegal war after illegal war, where is Congress? In this conversation with Margaret Hoover on PBS's Firing Line, we discuss why Congress's control over the decision to go to war is broken--and how we might fix it. www.youtube.com/watch?v=3N7N...

This conversation with Margaret Hoover on PBS's Firing Line about Congress and its war powers explores what's gone wrong--and how we might fix it.

"Legislators see themselves first and foremost as team players for their parties," says Philip Wallach. "They don't see their job as placing limits on the president," says @oonahathaway.bsky.social. "They see their job as enabling him." TONIGHT 8:30 pm ET @pbs.org listings: to.pbs.org/39hI6Tf

If Congress doesn’t do its job, “you end up with something closer to a monarchy or a dictatorship,” says @oonahathaway.bsky.social. “The whole reason for the revolution was to reject that form of government…When the president is able to act without any checks from Congress, all of that goes away.”

"Mr. Hegseth has also boasted about his efforts to scale back what he has called 'stupid rules of engagement.' Oona Hathaway, a professor of international law at Yale Law School, said those rules 'were developed precisely to prevent this kind of civilian harm'. . ." www.nytimes.com/interactive/...

What's wrong with Congress--and how can it be fixed? Margaret Hoover hosts a forum on the role of Congress, war powers, and reform at @hofstrau.bsky.social with AEI Senior Fellow Philip Wallach and Yale Law School Prof. @oonahathaway.bsky.social. FRIDAY @pbs.org Local listings: to.pbs.org/39hI6Tf

Mr Trump had threatened to wipe out a "whole civilisation" in Iran - and target civilian infrastructure like bridges and power plants if a deal was not met. Now a ceasefire is in place with negotiations to get underway in Pakistan this weekend. I speak with ABC: www.abc.net.au/listen/progr...

The rest of the world is trying to figure out what the heck is going on here in the United States. Here's a conversation with Radio New Zealand shortly after the ceasefire announcement: www.rnz.co.nz/national/pro...

I am getting a lot of questions about whether Trump's threats alone are illegal. The answer is yes. 1. First, Additional Protocol I states “Acts or threats of violence the primary purpose of which is to spread terror among the civilian population are prohibited.” (also DOD LOW Manual §5.2.2) 1/

I spoke to the Christian Science Monitor about Trump's threats to carry out mass war crimes. Though there appears to be a ceasefire (thank goodness), the threats have done irreparable damage to U.S. standing and moral authority. We will pay the cost for decades. www.csmonitor.com/World/2026/0...

Trump has threatened to bomb power plants, bridges, and other civilian infrastructure. If he carries out those threats, those acts would constitute war crimes. Listen to my conversation with @npr.org's @hereandnow.bsky.social: www.wbur.org/hereandnow/2...

This will be exhibit A in future war crimes trials if he carries out his threats. Tragically, it's those following the manifestly unlawful orders that are the ones most likely to be held to account.

The postwar global legal order is imperfect, to be sure, but it has brought unprecedented peace for eight decades. President Trump is throwing that all away. Glad to talk to Yola Verbruggen for "The UN, the international order and the ‘Board of Peace" www.ibanet.org/The-UN-the-i...

Great conversation with @sranderson.bsky.social and Missy Ryan on @npr.org's 1A today about President Trump's threats to target electricity-generating stations and other civilian infrastructure--and why carrying out those threats would be a war crime. the1a.org/segments/if-...

Glad to talk to Frontlines & Backrooms about the legality of the Iran war, the absence of an imminent threat, and what it means when powerful states act outside the UN Charter without meaningful response from the international community. Listen here: open.spotify.com/episode/2RBS...

“If these threatened attacks were to be carried out, they would constitute war crimes . . . Immiserating the civilian population for bargaining leverage is not lawful." Glad to talk to Saeed Shah for this story @theguardian.com: www.theguardian.com/world/2026/a...

The Iran war--and the way it is being waged--is "so clearly unlawful and deeply misguided." Glad to talk to Edward Wong for this piece @nytimes.com www.nytimes.com/2026/04/05/u...

Trump's aides are telling him that destroying Iran's infrastructure is fair game. They are wrong. They are advocating war crimes. Unfortunately, the targeting of infrastructure is far from new. See: "The Dangerous Rise of 'Dual-Use' Objects in War": papers.ssrn.com/sol3/papers....

Over 100 international lawyers (including me) warn that U.S. strikes on Iran violate the UN Charter and may be war crimes. Read the letter here: www.justsecurity.org/135423/profe...

The U.S. hit another school, together with a sports hall, killing and injuring many civilians. Even if it was a "mistake," it could still be a war crime if the strike was taken recklessly. Read more in "'Mistakes' in War": papers.ssrn.com/sol3/papers.... www.nytimes.com/2026/03/29/w...

As Trump prepares to send thousands more U.S. soldiers to the region without Congressional approval, the number of U.S. casualties is growing. defensescoop.com/2026/03/24/i...

The Constitution gives Congress alone the power to declare war, but modern presidents have asserted broad authority to use military force. Trump has now taken it to an extreme. Glad to talk with Sam Gringlas @npr.org for this important story. Listen (or read) here: www.npr.org/2026/03/10/n...

I spoke with BBC News for this important story about the U.S. air strike on an Iranian girls' school. Take a listen: www.bbc.com/audio/play/w...

"The Iran War marks the second time in two months that Donald Trump decapitated a country without real legal justification. But is this any different from the many times that past U.S. presidents—and other great powers—have violated international law?" Listen: carnegieendowment.org/podcasts/the...