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DISARMAMENT & SECURITY .

An article from Just Security

The United States and Israel initiated strikes on Iran over one month ago, on February 28, 2026. The attack was a clear violation of the United Nations Charter. The conduct of the war, and statements of U.S. officials, also raise serious concerns about violations of international humanitarian law, including potential war crimes. We have written the below statement together with over 100 U.S.-based international law experts, to detail our profound concerns about the war. The letter is signed by international law experts across the United States, including senior professors; leaders of prominent international law associations, non-governmental organizations, and legal clinics; former government legal advisors; and military law experts and former Judge Advocates General (JAGs).

Letter of over 100 international law experts on Iran war
 
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. Aceves

Chief Justice Roger Traynor Professor of Law

California Western School of Law

E. Tendayi Achiume

Professor of Law

Stanford Law School

Rabiat Akande

Wilson H. Elkins Chair and Associate Professor

University of Maryland School of Law

Susan Akram

Clinical Professor of Law

Director, International Human Rights Clinic

Boston University School of Law

Philip Alston

John Norton Pomeroy Professor of Law

NYU School of Law

José E. Alvarez

Herbert and Rose Rubin Professor of International Law

NYU School of Law

Faculty Director, US-Asia Law Institute

Diane Marie Amann

Visiting Professor, LSE Law School

Special Adviser to the International Criminal Court Prosecutor on Children in & affected by Armed Conflict (2012-2021)

Baher Azmy

Legal Director

Center for Constitutional Rights

Sandra L. Babcock

Clinical Professor of Law

Director, International Human Rights Clinic

Cornell Law School

Aslı Ü. Bâli

Howard M. Holtzmann Professor of Law

Yale Law School

Carolyn P. Blum

Clinical Professor of Law, Emerita

Berkeley Law, University of California

Christine Bustany

Senior Lecturer in International Law

Fletcher School of Law and Diplomacy

Charli Carpenter

Professor of Political Science

University of Massachusetts Department of Political Science

Christina M. Cerna

Adjunct Professor of Law (ret.)

Georgetown University Law Centre

Inter-American Commission on Human Rights (ret.), OAS

Sandra Coliver

Former Executive Director

Center for Justice and Accountability

Jorge Contesse

Professor of Law

Rutgers Law School

Cody Corliss

Associate Professor of Law

West Virginia University College of Law

Avidan Y. Cover

Professor of Law

Case Western Reserve University School of Law

Rebecca Crootof

Nancy Litchfield Hicks Professor of Law

University of Richmond School of Law

Jamil Dakwar

Director, ACLU Human Rights Program

Adjunct Professor, New York University and Hunter College

Tom Dannenbaum

Professor of Law, Stanford Law School

Frank Stanton Professor of Nuclear Security

Senior Fellow, Freeman Spogli Institute for International Studies, Stanford University

Frederick T. Davis

Lecturer in Law, Columbia Law School
Principal,
Fred Davis Law Office

Christian M. De Vos

Visiting Assistant Professor

City University of New York School of Law

Laura Dickinson

Lyle T. Alverson Professor of Law

The George Washington University Law School

Stephanie Farrior

Professor of Law (ret.)

Eugene R. Fidell

Visiting Lecturer in Law

Senior Research Scholar

Yale Law School

Martin S. Flaherty

Charles and Marie Robertson Visiting Professor

School of Public and International Affairs,
Princeton University

Laurel Fletcher

Chancellor’s Clinical Professor of Law

UC Berkeley, School of Law

Claudia Flores

Clinical Professor of Law

Director, Allard K. Lowenstein International Human Rights Clinic

Faculty Co-Director, Orville H. Schell Jr. Center for International Human Rights

Yale Law School

Idriss Fofana

Assistant Professor of Law

Harvard Law School

Barbara Frey

Director Emerita, Human Rights Program

University of Minnesota

Hannah R. Garry

Clinical Professor of Law

Founding Faculty Director, Donna and Spencer Gilbert Global Justice & Human Rights Center

Founding Director, International Human Rights Clinic

University of Southern California (USC) Gould School of Law

James A. Goldston

Executive Director

Open Society Justice Initiative

Jonathan Hafetz

Professor of Law

Seton Hall Law School

Lisa Hajjar

Professor of Sociology

University of California – Santa Barbara

Rebecca Hamilton

Professor of Law

American University, Washington College of Law

Hurst Hannum

Professor Emeritus of International Law

Fletcher School of Law and Diplomacy

Tufts University

Oona A. Hathaway

Gerard C. and Bernice Latrobe Smith Professor of International Law, Yale Law School

Professor, Yale University Department of Political Science

Faculty, Jackson School of Global Affairs, Yale University

Director, Center for Global Legal Challenges, Yale Law School

President-elect, American Society of International Law

Adil Haque

Distinguished Professor of Law and Judge Jon O. Newman Scholar

Rutgers Law School

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Hadar Harris

Founder and Principal

Rights and Justice Consulting

Lindsay M. Harris

Professor of Law

Director, International Human Rights Clinic

University of San Francisco School of Law

Sarah Harrison

Former Associate General Counsel

Department of Defense

J. Benton Heath

Associate Professor of Law

Temple University School of Law

Paul Hoffman

Director, Defending Democracy Clinic

University of California at Irvine School of Law

Partner, Schonbrun DeSimone Seplow Harris & Hoffman, LLP

David B. Hunter

Professor Emeritus

American University Washington College of Law

Deena R. Hurwitz, Esq.
Founder of the International Human Rights Clinic at the University of Virginia

Rebecca Ingber

Professor of Law

Cardozo Law

Co-Director, Floersheimer Center for Constitutional Democracy
Senior Fellow, Reiss Center on Law and Security,
NYU School of Law

Former Counselor, Office of the Legal Advisor, U.S Department of State

Tejal Jesrani

Human Rights Clinical Instructor

Director, TrialWatch Project

Columbia Law School

Brett Jones

Charles E. Scheidt Human Rights Visiting Assistant Clinical Professor

Benjamin N. Cardozo School of Law

Dr Ioannis Kalpouzos

Visiting Professor

Harvard Law School

Jeffrey Kahn

Professor of Law

Director, Program on Law and Government

American University Washington College of Law

David Kaye

Clinical Professor of Law

UC Irvine School of Law

UN Special Rapporteur on freedom of opinion and expression (2014 – 2020)

U.S. Member, European Commission for Democracy through Law (“Venice Commission”)

Pardiss Kebriaei

Senior Staff Attorney

Center for Constitutional Rights

Michael J. Kelly

Professor of Law

Senator Allen A. Sekt Endowed Chair in Law

Director, Kaiman Center for International Criminal Justice & Holocaust Studies

Creighton University

Jocelyn Getgen Kestenbaum

Professor of Law

Benjamin N. Cardozo School of Law

John H. Knox

Henry C. Lauerman Professor of International Law

Wake Forest University School of Law

Former UN Special Rapporteur on human rights and the environment

Harold Hongju Koh

Sterling Professor of International Law

Yale Law School

Steven Arrigg Koh

R. Gordon Butler Scholar in International Law

Boston University School of Law

Jeremy Konyndyk

President, Refugees International

David A. Koplow

Scott K. Ginsburg Professor of Law

Georgetown University Law Center

Christopher Kutz

C. William Maxeiner Distinguished Professor of Law

Philosophy and Political Science (by courtesy)

Berkeley Law School, UC Berkeley

Beatrice Lindstrom

Senior Clinical Instructor and Lecturer on Law

Harvard Law School

Katerina Linos

I. Michael Heyman Professor of Law

Co-Faculty Director, Miller Institute for Global Challenges and the Law

UC Berkeley, School of Law

Bert Lockwood

Distinguished Service Professor

Director of the Urban Morgan Institute for Human Rights
University of Cincinnati College of Law

Editor-in-Chief, Human Rights Quarterly

David Luban

Distinguished University Professor

Georgetown University Law Center

Kate Mackintosh

Executive Director, Professor from Practice

UCLA’s The Promise Institute for Human Rights (Europe)

David G. Mandel-Anthony

Faculty 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 State

Sarah Margon

Founder and Principal, Windsong Advisory

Former Director of US Foreign Policy at Open Society Foundations

Joseph Margulies

Professor of the Practice of Government

Cornell University

Craig Martin

Professor of Law

Co-Director, International and Comparative Law Center

Washburn University School of Law

Elisa Massimino

Visiting Professor of Law
Executive
Director, Human Rights Institute

Georgetown University Law Center

Daniel Maurer

Associate Professor of Law, Ohio Northern University Pettit College of Law

Advisor, Center for Military Law & Policy, Texas Tech University School of Law

Board of Directors, National Institute of Military Justice
Lieutenant Colonel, U.S. Army (ret.)

Juan E. Mendez

Professor of International Law (ret.)

Former UN Special Rapporteur on Torture (2010-2016)

Washington College of Law, American University

Gay J. McDougall

Former Vice Chair and 3-term Member, UN Committee on the Elimination of Racial Discrimination

Former UN Special Rapporteur on Minorities (2005-2011)
MacArthur Award Fellow, 1999

Senior Fellow and Distinguished Scholar-in-Residence

Leitner Center for International Law and Justice / Center for Race, Law and Justice

Fordham University School of Law

Margaret E. McGuinness

Professor of Law

Co-Director, Center for International and Comparative Law

St. John’s University School of Law

Chi Adanna Mgbako

Clinical Professor of Law

Director, Walter Leitner International Human Rights Clinic
Fordham Law School

Zinaida Miller

Professor of Law & International Affairs

Northeastern University

Saira Mohamed

Agnes Roddy Robb Chair in Jurisprudence, Ethics, and Social Responsibility

Professor of Law

UC Berkeley, School of Law

Bridget Moix

General Secretary, Friends Committee on National Legislation

Priyanka Motaparthy

Director, Center for International Human Rights

Clinical Professor

Northwestern Pritzker School of Law

Karen Musalo

Bank of America Foundation Chair in International Law

Professor & Director, Center for Gender & Refugee Studies

U.C. Law, San Francisco

Aryeh Neier

President Emeritus, Open Society Foundations

Former Executive Director, Human Rights Watch

Former Executive Director, American Civil Liberties Union

Mary Ellen O’Connell

Robert and Marion Short Professor of Law

Concurrent Professor of International Peace Studies

University of Notre Dame

Diane Orentlicher

Professor Emerita

American University Washington College of Law

Arzoo Osanloo

Professor of Anthropology

Co-Director of the Human Rights Initiative

Princeton University

Jessica Peake

Director, International & Comparative Law Program

UCLA School of Law

Stephen J. Rapp

Senior Fellow, Center for National Security Law, Georgetown Law School

Former US Ambassador-at-Large for Global Criminal Justice (2009-2015)

Paul Rink

Associate Professor of Law

Seton Hall Law School

Francisco J. Rivera Juaristi

Clinical Professor of Law

Santa Clara Law

Scott Roehm

Adjunct Professor of Law

Georgetown Law School

Dr. Cesare P.R. Romano

Professor of Law

W. Joseph Ford Fellow

Loyola Law School, Los Angeles

Gabor Rona

Professor of Practice

Cardozo Law School

Naomi Roht-Arriaza

Distinguished Professor of Law Emerita

UC Law San Francisco

Brad R. Roth

Professor of Political Science and Law

Wayne State University

Kenneth Roth

Charles and Marie Robertson Visiting Professor

Princeton School of Public and International Affairs

Former Executive Director, Human Rights Watch

Susana SáCouto

Professorial Lecturer-in-Residence

Director, War Crimes Research Office

Director, Summer Law Program in The Hague

American University Washington College of Law

Leila Nadya Sadat

James Carr Professor of International Criminal Law

Washington University School of Law

Director, Crimes Against Humanity Initiative

Chair, International Law Association (American Branch)

Former Special Advisor on Crimes Against Humanity to the ICC Prosecutor (2013-2023)

Margaret L. Satterthwaite

Professor of Law
, NYU School of Law

Beth Van Schaack

Former Ambassador-at-Large for Global Criminal Justice, U.S. State Department

Visiting Fellow (Feb. 2026 – June 2026)

European University Institute

Distinguished Fellow

Center for Human Rights & International Justice,
Stanford University

Michael P. Scharf

President of the American Branch of the International Law Association

Joseph C. Hostetler – BakerHostetler Professor of Law

Case Western Reserve University School of Law

Michael N. Schmitt

Professor of International Law, University of Reading

Professor Emeritus, US Naval War College

Former G. Norman Lieber Distinguished Scholar, West Point

Steven M. Schneebaum

Adjunct Professor
Johns Hopkins School of Advanced International Studies

Visiting Professor, Tashkent State University of Law, Uzbekistan

Eric Schwartz

Professor of Public Affairs

Chair, Global Policy

University of Minnesota

Elizabeth Shackelford

Distinguished Lecturer

Dartmouth College

Gregory Shaffer

Scott K. Ginsburg Professor of International Law

Georgetown University Law Center

Dinah Shelton

Manatt/Ahn Professor of Law (Emeritus)
The George Washington University Law School

Rebecca Shoot

Co-Convener, Washington Working Group for the International Criminal Court
Co-Convener, ImPact Coalition on Strengthening International Judicial Institutions

James Silk

Binger Clinical Professor Emeritus of Human Rights

Yale Law School

Matiangai Sirleaf

Nathan Patz Professor of Law

University of Maryland Francis King Carey School of Law
Professor, Department of Epidemiology and Public Health
University of Maryland School of Medicine

David Sloss

John A. and Elizabeth H. Sutro Professor of Law

Santa Clara University School of Law

Stephan Sonnenberg

Associate Professor of Practice

Wesleyan University

Milena Sterio

James A. Thomas Distinguished Professor of Law & LLM Programs Director

Cleveland State University College of Law

Jonathan Tracy

Former Judge Advocate, U.S. Army

Jennifer Trahan

Clinical Professor and Director of the Concentration in International Law and Human Rights

NYU Center for Global Affairs

Convenor, The Global Institute for the Prevention of Aggression

Rachel E. VanLandingham

Lieutenant Colonel (USAF) (ret.)
Professor of Law & Associate Dean for Research, Southwestern Law School

President Emerita & Director, National Institute of Military Justice

* Signatories are signing in their individual capacities and affiliations are for identification purposes only.

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