International Law Experts: U.S. Violates U.N. Charter, Commits War Crimes in Iran

In its execution of Donald Trump’s impulsive change-the-subject war on Iran, the United States is violating the United Nations Charter and committing war crimes, say over a hundred U.S.-based experts on international law:

We write to express our concern about 1) jus ad bellum, or the decision to go to war, 2) jus in bello, or the conduct of hostilities, 3) rhetoric and threats from senior U.S. officials and their allies, which portend further abuses, and 4) the decimation of civilian harm mitigation structures within the U.S. government as a part of U.S. Secretary of Defense Pete Hegseth’s “gloves off” approach to warfare.

1. Jus ad bellum concerns: The strikes launched by the United States and Israel on February 28, 2026 clearly violated the United Nations Charter prohibition on the use of force. Force against another state is only permitted in self-defense against an actual or imminent armed attack or where authorized by the UN Security Council. The Security Council did not authorize the attack. Iran did not attack Israel or the United States. Despite the Trump administration’s varied and sometimes conflicting claims to the contrary, there is no evidence that Iran posed an imminent threat that could ground a self-defense claim. Many international law experts have concluded that Israel and the United States’ actions violate the UN Charter, including the President and President-elect of the American Society of International Law, and the President of the American Branch of the International Law Association; UN Secretary-General António Guterres also condemned the attacks as undermining international peace and security.

2. Concerns about violations of international humanitarian law: The laws of armed conflict constrain the conduct of hostilities of all parties to the ongoing conflict. We are concerned that these fundamental rules may have been violated, including in the context of reported strikes on civilians and civilian objects such as political leaders who have no military role, oil and gas infrastructure, including South Pars, and water desalination plants. On March 19, UN High Commissioner for Human Rights Volker Türk condemned strikes on energy infrastructure, noting their “disastrous” impacts for civilians.

We are seriously concerned about strikes that have hit schools, health facilities, and homes. The Iranian Red Crescent reports that “67,414 civilian sites have been struck, of which 498 are schools and 236 health facilities.” A report by leading civil society organizations found that at least 1,443 Iranian civilians, including 217 children, were killed by U.S. and Israeli forces between February 28 and March 23.

The strike on Minab primary school is particularly concerning. On February 28, Shajareh Tayyebeh Primary School in Minab, Iran, was struck, resulting in the deaths of at least 175 people, many of them children, according to Iranian officials. Based on easily accessible online information and commercially available satellite imagery, it appears the building had been used as a school for a decade. President Trump denied U.S. responsibility, falsely stating that “It was done by Iran.” However, a preliminary investigation by the Department of Defense reportedly determined that the U.S. conducted the strike, and the targeting had been based on outdated intelligence. The strike likely violates international humanitarian law, and if evidence is found that those responsible were reckless, it could also be a war crime. The strike is among the deadliest single attacks by the U.S. military on civilians in recent decades.

3. Concerns about rhetoric and threats from senior officials. We are deeply concerned about the dangerous rhetoric government officials have engaged in during the war, including:

a. Threatened denial of quarter: On March 13, Secretary of Defense Pete Hegseth stated “We will keep pushing, keep advancing, no quarter, no mercy for our enemies.” In international law, it is “especially forbidden” to “declare that no quarter will be given,” a prohibition also set out in the Department of Defense’s own law of war manual. Hegseth’s statement likely violates international humanitarian law as well as the U.S. War Crimes statute 18 U.S.C. 2441. Ordering or threatening no quarter is a war crime.

b. Dismissal of rules of engagement and international law: Secretary of Defense Hegseth’s “no quarter” statement followed similarly alarming statements by the Secretary, including on September 25, 2025 and March 2, 2026 that the U.S. does not fight with “stupid rules of engagement.” On January 8, 2026 President Trump had made the disturbing comment that “I don’t need international law.” On March 13, he stated that the U.S. may conduct strikes on Iran “just for fun.”

c. Threats on energy infrastructure: President Trump threatened on March 13, 2026: “I could take out things within the next hour, power plants that create the electricity, that create the water… We could do things that would be so bad they could literally never rebuild as a nation again.” International law protects from attack objects indispensable to the survival of civilians, and the attacks threatened by Trump, if implemented, could entail war crimes. On March 21, President Trump further threatened to “obliterate” power plants in Iran. U.S. Ambassador to the United Nations, Mike Waltz, defended power plant attacks the next day, and also said that striking nuclear power plants was not off the table. It is prohibited to attack civilian energy infrastructure. If a power plant has both civilian and military purposes (“dual-use”), it may be considered a military objective where it makes “an effective contribution to military action” and the attack “offers a definite military advantage.” However, any strike must respect the principles of proportionality and precautions in attack. The proportionality principle prohibits attacks expected to cause incidental civilian harm that would be excessive in relation to the military advantage. The civilian harm to be considered includes foreseeable reverberating or indirect harm. In any attack, “all feasible precautions” must be taken to avoid civilian harm.

Attacks on nuclear power plants, even if they have a military purpose, require particular care because of the high risk of releasing radiation and radioactive material and consequent severe harm to the civilian population. Such a strike could harm the health and safety of millions of civilians.  On March 23, 2026, the ICRC President Mirjana Spoljaric Egger expressed her deep concern, noting that “War on essential infrastructure is war on civilians” and described threats to nuclear power plants as “Most alarming.”

4. Concerns about institutional safeguards against further violations: Since the start of the second Trump administration, the Defense Department under Secretary Hegseth has deliberately and systematically weakened the protections meant to ensure compliance with international humanitarian law. This includes removing senior military lawyers without publicly citing misconduct, and replacing the Army, Navy, and Air Force judge advocates general, directly undermining legal oversight of combat operations. It has also abolished “civilian environment teams” and other mechanisms specifically designed to limit harm to civilians during operations. The 2026 National Defense Strategy omits references to civilian protection and international law entirely. These changes are especially concerning in light of Defense Secretary Pete Hegseth’s comments that rules of engagement interfere with “fighting to win.”

We are gravely concerned that the conduct and threats outlined here are causing serious harm to civilians in the Middle East, and that they also contribute to escalating the conflict, damaging the environment and the global economy, and that they risk degrading the rule of law and fundamental norms that protect every nation’s civilians. Public statements by senior officials indicate an alarming disrespect for the rules of international humanitarian law accepted by states, and which protect both civilians and members of the armed forces.

We urge U.S. government officials to uphold the UN Charter, international humanitarian law, and human rights law at all times, and to publicly make clear U.S. commitment to and respect for norms of international law [Tom Dannenbaum, Rebecca Hamilton, Adil Ahmad Haque, Oona A. Hathaway,  Gabor Rona, et al., “Over 100 International Law Experts Warn: U.S. Strikes on Iran Violate UN Charter and May Be War Crimes,” Just Security, 2026.04.02].

Trump says Iran belongs in the Stone Age… but it’s the United States that’s acting like the brutish caveman with no strategy or sense of human dignity.