What is a war crime? A former U.S. State Department foreign affairs officer provides a primer
Defendants sit in the dock at the International Military Tribunal trial of war criminals in Nuremberg, Germany, in November 1945. (Photo: Wikimedia Commons/ Raymond D’Addario.)

What is a war crime? A former U.S. State Department foreign affairs officer provides a primer

Jeffrey Fields of international relations at USC Dornsife discusses the definition and origin of the term, and whether President Biden is correct in his allegations against Russia.
ByJim Key and Darrin S. Joy

President Joe Biden and other world leaders have asserted that Russia and its president, Vladimir Putin, are guilty of war crimes committed during Russia’s war against Ukraine. But what exactly qualifies as a war crime and how does the international community level charges and determine guilt or innocence?

Jeffrey Fields, associate professor of the practice of international relations at the USC Dornsife College of Letters, Arts and Sciences, provides answers to these and several related questions.

Fields is a former senior adviser and political-military analyst with the U.S. Department of Defense and former foreign affairs officer with the U.S. State Department. His research and teaching focus on American foreign policy, diplomacy and international security. He earned his PhD at USC Dornsife in 2007.


What is a war crime?

A war crime is a violation of international and customary laws governing the conduct of warfare and armed conflict. The Rome Statute of the International Criminal Court (ICC) defines war crimes as “grave breaches of the Geneva Conventions of 12 August 1949,” which includes behavior such as torture; willfully causing great suffering and bodily harm; and extensive destruction and appropriation of property, not justified by military necessity.

The Geneva Conventions were designed especially to protect civilians and noncombatants. The Conventions also regulate the treatment of sick and wounded combatants, treatment and repatriation of prisoners of war, and protection for hospitals. (Notably, they do not use the term “war crime” but rather lay out provisions for moral and ethical conduct during warfare.)

War crimes in general refer to intentionally causing excessive destruction and intentionally harming or killing civilians or prisoners of war. This includes rape and sexual violence, torture, genocide and forced displacement.

Where does the term come from?

The historian Michael Bryant, an expert on the Holocaust’s impact on the law and human rights, dates the origin of the English language term “war crimes” to a 1906 book on international law, though the idea that certain behaviors and weapons were out of bounds in armed conflict certainly predates the 20th century. International treaties such as the Hague Conventions of 1899 and 1907 established some laws and customs of war.

The Nuremberg Trials that took place at the conclusion of World War II established similar conceptions of what constituted a war crime, and the term subsequently began to be used more commonly, though it was in use in the aftermath of German atrocities committed during World War — the term first appears in The New York Times in 1921.

What does it mean to accuse another country or government of war crimes?

Accusing a country or individual is both powerful rhetoric and sometimes a call for the prosecution of individuals accused of violating international standards. President Biden remarked in mid-March that he thought Vladimir Putin was a war criminal. British Prime Minister Boris Johnson has also said that Russia had committed war crimes in Ukraine. It is unlikely, however, that Putin will ever stand trial for war crimes, and thus, the accusation is one more of recognition than a call for prosecution.

The term refers to many things and behaviors, and Biden did not cite any specific actions or incidents. The International Criminal Court, however, has opened an investigation to events in Ukraine that it deemed possible crimes and that fall within its jurisdiction.

How is it determined if a war crime was committed, and what’s the punishment?

There are three main mechanisms today that would deal with war crimes prosecutions: The International Court of Justice (ICJ), the International Criminal Court (ICC), and special ad hoc tribunals such as the one set up to deal with war crimes that occurred during conflicts in the Balkans in the 1990s.

These courts and tribunals set their own jurisdictions, rules and procedures. The ICJ, for example, is the principal judicial organ of the United Nations and only states (versus individuals) can appear before the court.

The ICC has well-established procedures for handling alleged cases of genocide, war crimes and crimes against humanity. It can “impose a prison sentence, to which may be added a fine or forfeiture of the proceeds, property and assets derived directly or indirectly from the crime committed.” The ICC does not impose death sentences, and the maximum prison sentence is 30 years, unless the court deems a particular case “extreme.”

What does it mean to convene a war crimes tribunal?

War crimes tribunals are ad hoc courts established to try individuals accused of war crimes and crimes against humanity specific to a conflict. For example, the Nuremberg Trials, technically called the International Military Tribunal at Nuremberg (IMT), were held to deal with Nazi war crimes committed during WW II. (A similar tribunal was established to deal with war crimes committed by the Empire of Japan.) The allies, principally France, the Soviet Union, the United Kingdom and the United States, established the IMT.

The U.N. Security Council established the International Criminal Tribunal for Rwanda to “prosecute persons responsible for genocide and other serious violations of international humanitarian law committed in the territory of Rwanda and neighboring States, between 1 January 1994 and 31 December 1994.”

These tribunals typically are disbanded after completion of proceedings, though they often are in existence for many years.

Have leaders of a country ever been convicted and punished for war crimes?

Military commanders, combatants and other politicians constitute the majority of people convicted and punished for war crimes. But some notable heads of state have been prosecuted in war crimes tribunals:

  • Charles Taylor, the former president of Liberia, was convicted in 2012 of crimes against humanity for atrocities committed in Sierra Leone and sentenced to 50 years in prison.
  • Slobadan Milošević, the former president of Serbia, was standing trial for war crimes in International Criminal Tribunal for the former Yugoslavia in the Hague but died before completion of the trial. Radovan Karadžić, sometimes referred to as the Butcher of Bosnia, was found guilty of war crimes and crimes against humanity in the same court and was sentenced to life imprisonment.
  • Saddam Hussein was convicted of crimes against humanity by a court overseen by the Iraqi Interim Government and executed in 2006.

What is happening with respect to Ukraine?

The International Criminal Court opened an investigation into alleged crimes committed by Russia in Ukraine. Ukraine is not a party to the Rome Statute of the ICC. However, it has “exercised its prerogatives to accept the Court’s jurisdiction over alleged crimes under the Rome Statute occurring on its territory,” and on March 2, the ICC prosecutor announced an investigation had been opened based on referrals from dozens of state parties to the ICC.

Is Russia committing genocide in Ukraine?

President Joe Biden accused Russia of committing genocide in Ukraine. Speaking to reporters and referring to his first intimation of this, Biden said, “Yes, I called it genocide, because it’s become clearer and clearer that Putin is just trying to wipe out even the idea of being Ukrainian, and the evidence is mounting.”

There is no doubt that Russia has committed mass atrocities in Ukraine, targeting and executing civilians and wantonly destroying infrastructure. These are war crimes as described above. But is the Russian killing of Ukrainians genocide as President Biden alleged? It is difficult to say. The 1948 Convention on the Prevention and Punishment of the Crime of Genocide defines genocide as “acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group” (emphasis added). Those acts are any of:

(a) Killing members of the group;
(b) Causing serious bodily or mental harm to members of the group;
(c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part;
(d) Imposing measures intended to prevent births within the group;
(e) Forcibly transferring children of the group to another group.

So while acts that constitute genocide are clearly defined, whether or not Russia’s actions in Ukraine are genocide depends on Moscow’s intent, which is difficult to discern. Targeting and even executing civilians would be a war crime but not automatically genocide without evidence of intent to systematically eliminate the Ukrainian people.