New Delhi: The United States and Israel initiated strikes on Iran over one month ago, on February 28. The result has been the deaths of thousands, with far more displaced and key trade channels blocked.Over 100 international law experts across the United States, including senior professors, leaders of prominent international law associations, non-governmental organisations, and legal clinics, former government legal advisors, military law experts and former Judge Advocates General (JAGs), have written a letter to detail their profound concerns about the war.The full letter is below.§We, the undersigned U.S.-based international law experts, professors, and practitioners write to express profound concern about serious violations of international law and alarming rhetoric by the United States, Israel, and Iran in the present armed conflict in the Middle East.Due to our connection to the United States, our focus here is on the conduct of the U.S. government, but we remain concerned about the risk of atrocities across the region including the continuing risks posed by the Iranian government to Iranians through violent crackdowns on dissent, and to civilians across the Middle East through Iran’s ongoing unlawful strikes on civilian infrastructure using explosive weapons in densely populated areas.One month has passed since the United States and Israel launched strikes across Iran. The initiation of the campaign was a clear violation of the United Nations Charter, and the conduct of United States forces since, as well as statements made by senior government officials, raise serious concerns about violations of international human rights law and international humanitarian law, including potential war crimes.We collectively affirm the importance of equal application of international law to all, including countries that hold themselves out as global leaders. Recent statements from senior U.S. government officials describing the rules governing military engagement as “stupid” and prioritizing “lethality” over “legality” are profoundly alarming and dangerously short-sighted. These claims, particularly in combination with the observable conduct of U.S. forces, are harming the international legal order and the system of international law that we have devoted our lives to promoting.The war, which is costing U.S. taxpayers between $1-2 billion each day, is imposing significant harm to civilians in the region, has resulted in the loss of hundreds of civilian lives across the Middle East, and is causing serious environmental and economic harms.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.We remind all states of their legal obligations not to aid or assist the United States, Israel, or Iran in the commission of internationally wrongful acts, as well as to cooperate to bring to an end through lawful means serious breaches of peremptory norms of general international law (jus cogens) including the prohibition of aggression and the basic rules of international humanitarian law.We also urge the U.S. governments’ allies and cooperating partners to take steps to respect and ensure respect for international humanitarian law, in line with Common Article 1 of the Geneva Conventions and associated customary international law. The United States has itself acknowledged that states should seek to promote adherence by others to international humanitarian law. The International Committee of the Red Cross 2016 Commentary on the First Geneva Convention of 1949 provides that a state is “in a unique position to influence the behavior” of partner states where the state “participates in the financing, equipping, arming or training of the armed forces of a Party to a conflict, even plans, carries out and debriefs operations jointly with such forces.”Signed,William J. AcevesChief Justice Roger Traynor Professor of LawCalifornia Western School of LawE. Tendayi AchiumeProfessor of LawStanford Law SchoolRabiat AkandeWilson H. Elkins Chair and Associate ProfessorUniversity of Maryland School of LawSusan AkramClinical Professor of LawDirector, International Human Rights ClinicBoston University School of LawPhilip AlstonJohn Norton Pomeroy Professor of LawNYU School of LawJosé E. AlvarezHerbert and Rose Rubin Professor of International LawNYU School of LawFaculty Director, US-Asia Law InstituteDiane Marie AmannVisiting Professor, LSE Law SchoolSpecial Adviser to the International Criminal Court Prosecutor on Children in & affected by Armed Conflict (2012-2021)Baher AzmyLegal DirectorCenter for Constitutional RightsSandra L. BabcockClinical Professor of LawDirector, International Human Rights ClinicCornell Law SchoolAslı Ü. BâliHoward M. Holtzmann Professor of LawYale Law SchoolThomas B. Becker, Jr.Legal & Policy Director, University Network for Human RightsCarolyn P. BlumClinical Professor of Law, EmeritaBerkeley Law, University of CaliforniaChristine BustanySenior Lecturer in International LawFletcher School of Law and DiplomacyCharli CarpenterProfessor of Political ScienceUniversity of Massachusetts Department of Political ScienceChristina M. CernaAdjunct Professor of Law (ret.)Georgetown University Law CentreInter-American Commission on Human Rights (ret.), OASSandra ColiverFormer Executive DirectorCenter for Justice and AccountabilityJorge ContesseProfessor of LawRutgers Law SchoolCody CorlissAssociate Professor of LawWest Virginia University College of LawAvidan Y. CoverProfessor of LawCase Western Reserve University School of LawRebecca CrootofNancy Litchfield Hicks Professor of LawUniversity of Richmond School of LawJamil DakwarDirector, ACLU Human Rights ProgramAdjunct Professor, New York University and Hunter CollegeTom DannenbaumProfessor of Law, Stanford Law SchoolFrank Stanton Professor of Nuclear SecuritySenior Fellow, Freeman Spogli Institute for International Studies, Stanford UniversityFrederick T. DavisLecturer in Law, Columbia Law SchoolPrincipal, Fred Davis Law OfficeChristian M. De VosVisiting Assistant ProfessorCity University of New York School of LawLaura DickinsonLyle T. Alverson Professor of LawThe George Washington University Law SchoolJoseph F.C. DiMentoDistinguished Professor of LawUniversity of California IrvineStephanie FarriorProfessor of Law (ret.)Eugene R. FidellVisiting Lecturer in LawSenior Research ScholarYale Law SchoolMartin S. FlahertyCharles and Marie Robertson Visiting ProfessorSchool of Public and International Affairs, Princeton UniversityLaurel FletcherChancellor’s Clinical Professor of LawUC Berkeley, School of LawClaudia FloresClinical Professor of LawDirector, Allard K. Lowenstein International Human Rights ClinicFaculty Co-Director, Orville H. Schell Jr. Center for International Human RightsYale Law SchoolIdriss FofanaAssistant Professor of LawHarvard Law SchoolBarbara FreyDirector Emerita, Human Rights ProgramUniversity of MinnesotaHannah R. GarryClinical Professor of LawFounding Faculty Director, Donna and Spencer Gilbert Global Justice & Human Rights CenterFounding Director, International Human Rights ClinicUniversity of Southern California (USC) Gould School of LawJames A. GoldstonExecutive DirectorOpen Society Justice InitiativeJonathan HafetzProfessor of LawSeton Hall Law SchoolLisa HajjarProfessor of SociologyUniversity of California – Santa BarbaraRebecca HamiltonProfessor of LawAmerican University, Washington College of LawHurst HannumProfessor Emeritus of International LawFletcher School of Law and DiplomacyTufts UniversityOona A. HathawayGerard C. and Bernice Latrobe Smith Professor of International Law, Yale Law SchoolProfessor, Yale University Department of Political ScienceFaculty, Jackson School of Global Affairs, Yale UniversityDirector, Center for Global Legal Challenges, Yale Law SchoolPresident-elect, American Society of International LawAdil HaqueDistinguished Professor of Law and Judge Jon O. Newman ScholarRutgers Law SchoolHadar HarrisFounder and PrincipalRights and Justice ConsultingLindsay M. HarrisProfessor of LawDirector, International Human Rights ClinicUniversity of San Francisco School of LawSarah HarrisonFormer Associate General CounselDepartment of DefenseJ. Benton HeathAssociate Professor of LawTemple University School of LawPaul HoffmanDirector, Defending Democracy ClinicUniversity of California at Irvine School of LawPartner, Schonbrun DeSimone Seplow Harris & Hoffman, LLPDavid B. HunterProfessor EmeritusAmerican University Washington College of LawDeena R. Hurwitz, Esq.Rebecca IngberProfessor of LawCardozo LawCo-Director, Floersheimer Center for Constitutional DemocracySenior Fellow, Reiss Center on Law and Security, NYU School of LawFormer Counselor, Office of the Legal Advisor, U.S Department of StateTejal JesraniHuman Rights Clinical InstructorDirector, TrialWatch ProjectColumbia Law SchoolBrett JonesCharles E. Scheidt Human Rights Visiting Assistant Clinical ProfessorBenjamin N. Cardozo School of LawKelsey Jost-CreeganLecturer in LawDeputy DirectorSmith Family Human Rights ClinicColumbia Law SchoolDr Ioannis KalpouzosVisiting ProfessorHarvard Law SchoolJeffrey KahnProfessor of LawDirector, Program on Law and GovernmentAmerican University Washington College of LawDavid KayeClinical Professor of LawUC Irvine School of LawUN Special Rapporteur on freedom of opinion and expression (2014 – 2020)U.S. Member, European Commission for Democracy through Law (“Venice Commission”)Pardiss KebriaeiSenior Staff AttorneyCenter for Constitutional RightsMichael J. KellyProfessor of LawSenator Allen A. Sekt Endowed Chair in LawDirector, Kaiman Center for International Criminal Justice & Holocaust StudiesCreighton UniversityJocelyn Getgen KestenbaumProfessor of LawBenjamin N. Cardozo School of LawJohn H. KnoxHenry C. Lauerman Professor of International LawWake Forest University School of LawFormer UN Special Rapporteur on human rights and the environmentHarold Hongju KohSterling Professor of International LawYale Law SchoolSteven Arrigg KohR. Gordon Butler Scholar in International LawBoston University School of LawJeremy KonyndykPresident, Refugees InternationalDavid A. KoplowScott K. Ginsburg Professor of LawGeorgetown University Law CenterChristopher KutzC. William Maxeiner Distinguished Professor of LawPhilosophy and Political Science (by courtesy)Berkeley Law School, UC BerkeleyBeatrice LindstromSenior Clinical Instructor and Lecturer on LawHarvard Law SchoolKaterina LinosI. Michael Heyman Professor of LawCo-Faculty Director, Miller Institute for Global Challenges and the LawUC Berkeley, School of LawBert LockwoodDistinguished Service ProfessorDirector of the Urban Morgan Institute for Human RightsUniversity of Cincinnati College of LawEditor-in-Chief, Human Rights QuarterlyDavid LubanDistinguished University ProfessorGeorgetown University Law CenterKate MackintoshExecutive Director, Professor from PracticeUCLA’s The Promise Institute for Human Rights (Europe)David G. Mandel-AnthonyFaculty Instructor, Binghamton University Institute for Genocide and Mass Atrocity Prevention (I-GMAP)Former Deputy to the Ambassador-at-Large for Global Criminal Justice, U.S. Department of StateSarah MargonFounder and Principal, Windsong AdvisoryFormer Director of US Foreign Policy at Open Society FoundationsJoseph MarguliesProfessor of the Practice of GovernmentCornell UniversityCraig MartinProfessor of LawCo-Director, International and Comparative Law CenterWashburn University School of LawElisa MassiminoVisiting Professor of LawExecutive Director, Human Rights InstituteGeorgetown University Law CenterDaniel MaurerAssociate Professor of Law, Ohio Northern University Pettit College of LawAdvisor, Center for Military Law & Policy, Texas Tech University School of LawBoard of Directors, National Institute of Military JusticeLieutenant Colonel, U.S. Army (ret.)Juan E. MendezProfessor of International Law (ret.)Former UN Special Rapporteur on Torture (2010-2016)Washington College of Law, American UniversityGay J. McDougallFormer Vice Chair and 3-term Member, UN Committee on the Elimination of Racial DiscriminationFormer UN Special Rapporteur on Minorities (2005-2011)MacArthur Award Fellow, 1999Senior Fellow and Distinguished Scholar-in-ResidenceLeitner Center for International Law and Justice / Center for Race, Law and JusticeFordham University School of LawMargaret E. McGuinnessProfessor of LawCo-Director, Center for International and Comparative LawSt. John’s University School of LawChi Adanna MgbakoClinical Professor of LawDirector, Walter Leitner International Human Rights ClinicFordham Law SchoolZinaida MillerProfessor of Law & International AffairsNortheastern UniversitySaira MohamedAgnes Roddy Robb Chair in Jurisprudence, Ethics, and Social ResponsibilityProfessor of LawUC Berkeley, School of LawBridget MoixGeneral Secretary, Friends Committee on National LegislationPriyanka MotaparthyDirector, Center for International Human RightsClinical ProfessorNorthwestern Pritzker School of LawKaren MusaloBank of America Foundation Chair in International LawProfessor & Director, Center for Gender & Refugee StudiesU.C. Law, San FranciscoAryeh NeierPresident Emeritus, Open Society FoundationsFormer Executive Director, Human Rights WatchFormer Executive Director, American Civil Liberties UnionMary Ellen O’ConnellRobert and Marion Short Professor of LawConcurrent Professor of International Peace StudiesUniversity of Notre DameDiane OrentlicherProfessor EmeritaAmerican University Washington College of LawArzoo OsanlooProfessor of AnthropologyCo-Director of the Human Rights InitiativePrinceton UniversityJessica PeakeDirector, International & Comparative Law ProgramUCLA School of LawStephen J. RappSenior Fellow, Center for National Security Law, Georgetown Law SchoolFormer US Ambassador-at-Large for Global Criminal Justice (2009-2015)Paul RinkAssociate Professor of LawSeton Hall Law SchoolFrancisco J. Rivera JuaristiClinical Professor of LawSanta Clara LawScott RoehmAdjunct Professor of LawGeorgetown Law SchoolDr. Cesare P.R. RomanoProfessor of LawW. Joseph Ford FellowLoyola Law School, Los AngelesGabor RonaProfessor of PracticeCardozo Law SchoolNaomi Roht-ArriazaDistinguished Professor of Law EmeritaUC Law San FranciscoBrad R. RothProfessor of Political Science and LawWayne State UniversityKenneth RothCharles and Marie Robertson Visiting ProfessorPrinceton School of Public and International AffairsFormer Executive Director, Human Rights WatchSusana SáCoutoProfessorial Lecturer-in-ResidenceDirector, War Crimes Research OfficeDirector, Summer Law Program in The HagueAmerican University Washington College of LawLeila Nadya SadatJames Carr Professor of International Criminal LawWashington University School of LawDirector, Crimes Against Humanity InitiativeChair, International Law Association (American Branch)Former Special Advisor on Crimes Against Humanity to the ICC Prosecutor (2013-2023)Margaret L. SatterthwaiteProfessor of LawNYU School of LawBeth Van SchaackFormer Ambassador-at-Large for Global Criminal Justice, U.S. State DepartmentVisiting Fellow (Feb. 2026 – June 2026)European University InstituteDistinguished FellowCenter for Human Rights & International Justice, Stanford UniversityMichael P. ScharfPresident of the American Branch of the International Law AssociationJoseph C. Hostetler – BakerHostetler Professor of LawCase Western Reserve University School of LawMichael N. SchmittProfessor of International Law, University of ReadingProfessor Emeritus, US Naval War CollegeFormer G. Norman Lieber Distinguished Scholar, West PointSteven M. SchneebaumAdjunct ProfessorJohns Hopkins School of Advanced International StudiesVisiting Professor, Tashkent State University of Law, UzbekistanEric SchwartzProfessor of Public AffairsChair, Global PolicyUniversity of MinnesotaElizabeth ShackelfordDistinguished LecturerDartmouth CollegeGregory ShafferScott K. Ginsburg Professor of International LawGeorgetown University Law CenterDinah SheltonManatt/Ahn Professor of Law (Emeritus)The George Washington University Law SchoolRebecca ShootCo-Convener, Washington Working Group for the International Criminal CourtCo-Convener, ImPact Coalition on Strengthening International Judicial InstitutionsJames SilkBinger Clinical Professor Emeritus of Human RightsYale Law SchoolMatiangai SirleafNathan Patz Professor of LawUniversity of Maryland Francis King Carey School of LawProfessor, Department of Epidemiology and Public HealthUniversity of Maryland School of MedicineDavid SlossJohn A. and Elizabeth H. Sutro Professor of LawSanta Clara University School of LawStephan SonnenbergAssociate Professor of PracticeWesleyan UniversityMilena SterioJames A. Thomas Distinguished Professor of Law & LLM Programs DirectorCleveland State University College of LawJonathan TracyFormer Judge Advocate, U.S. ArmyJennifer TrahanClinical Professor and Director of the Concentration in International Law and Human RightsNYU Center for Global AffairsConvenor, The Global Institute for the Prevention of AggressionRachel E. VanLandinghamLieutenant Colonel (USAF) (ret.)Professor of Law & Associate Dean for Research, Southwestern Law SchoolPresident Emerita & Director, National Institute of Military JusticeSalma WaheediInternational Human Rights Lawyer and MENA Legal AdvisorUniversity Network for Human RightsCarrie Booth WallingDirector, Human Rights ProgramUniversity of MinnesotaElisabeth WardClinical FacultyFounding Director, International Human Rights Law ClinicExecutive Director, International Human Rights Law InstituteDePaul University College of LawAllen S. WeinerSenior Lecturer in LawDirector, Stanford Program in International and Comparative LawStanford Law SchoolAlex WhitingProfessor of PracticeHarvard Law SchoolRichard Ashby WilsonProfessor of AnthropologyCo-Director, Human Rights InitiativePrinceton UniversityRichard J. WilsonProfessor of Law EmeritusAmerican University, Washington College of LawKatharine G. YoungProfessorBoston College Law School