Ukraine has claimed that Russia's transfer of thousands of children from Ukraine since Russia's invasion in February 2022 was a "genocidal crime." In the current conflict between Israel and the Palestinian Islamist militant group Hamas, some are accusing Israel of attempted genocide because of the Israeli airstrikes on the Gaza Strip, a retaliation to Hamas' terror attacks on October 7. 

But what exactly constitutes genocide, and when can the term be applied?

Defined as an intent to exterminate a particular group of people, the term genocide was first coined amid the horrors of the Holocaust during World War II.

Jewish-Polish lawyer Raphael Lemkin came up with the term for his 1944 book "Axis Rule in Occupied Europe," partly in response to Hitler's systematic murder of Jews by Nazi Germany. Lemkin lost his entire family, with the exception of his brother, to the Holocaust.

Lemkin campaigned to have genocide recognized as a crime under international law, paving the way for the adoption of the United Nations Genocide Convention in 1948, which came into effect in 1951.

Article Two of the convention defines genocide as any act "committed with intent to destroy, in whole or in part, a national, ethnic, racial or religious group."

Such acts could include killings, inflicting serious bodily or mental harm or life-threatening conditions, measures to prevent births and forcibly transferring children, according to the UN definition.

Who can be prosecuted?

The UN Genocide Convention states that everyone can be prosecuted and punished for genocide, including elected leaders.  

The International Criminal Court has a mandate to investigate and prosecute genocide, war crimes and crimes against humanity. According to its statutes, anyone who commits, orders, assists and even incites genocide can be prosecuted.

A separate court, the International Court of Justice at the Hague, deals with interstate disputes and can also rule that states are responsible for genocide.

Proving genocide isn't easy

"Very often the term genocide is used loosely in common language by people to refer to the biggest, gravest crime because somehow it sounds far worse than war crimes or crimes against humanity," Valerie Gabard, an expert on international law based in the Hague, told DW when asked about the term in Russia's invasion of Ukraine.

"But, legally speaking, the definition of genocide is very narrow," Gabard, who is co-founder of UpRights, a law consultancy, said.

"It's not a matter of numbers that decides whether there is genocide or not. The intention to physically exterminate a group is the main criterion for this crime," she said.

But experts say proving that "special intent" is not easy because often there is no direct evidence.

"The problem with proving genocidal intent is that you're likely not going to have perpetrators in court make some direct admission," William Schabas, professor of International Law at Middlesex University in London, told DW, also when asked about the term in relation to Russia's invasion.

"So the courts have to infer the intent of the perpetrators based on their conduct. So you have to rely on circumstantial evidence. And the rule is that it has to be beyond reasonable doubt. That's where it gets harder."

Genocide prosecutions can take time

Gabard, who has worked on international criminal tribunals for Cambodia, Rwanda and the former Yugoslavia, said the prosecution of genocide can take time.

"It takes very long, also because of the scale of the crimes," Gabard said.

"Generally, when you speak of genocide, there are lots of victims, and it takes a long time to investigate the crimes and to prove not only an intention to kill, but to kill people because they were part of a group."

Genocide or not?

In 2021, the US, Canadian and Dutch governments all accused China of committing genocide against the Uyghur people in Xinjiang, while several other countries brought parliamentary resolutions making the same accusation.

Experts, however, point to three genocides recognized to date by a court of law at an international level — Rwanda, where an estimated 800,000 Tutsis and moderate Hutus died in the 1994 genocide, the 1995 massacre at Srebrenica that was ruled to be genocide by the International Criminal Tribunal for the former Yugoslavia and the Khmer Rouge killings in Cambodia in the 1970s.

On the latter, there is disagreement over the fact that many of the victims of the Khmer Rouge were targeted because of their political or social status — putting them outside of the UN definition of genocide.

In 2010, the International Criminal Court issued an arrest warrant for Sudanese President Omar al-Bashir on genocide charges, accusing him of waging a campaign against the citizens of the region of Darfur.

"We have the legal definition of genocide being used in cases at the International Court of Justice and in the convictions of the Rwanda tribunal. We have a very well-established law of what genocide is." Schabas said.

"But then you have this phenomenon of attempts to use the label genocide that does not correspond to the legal definition of genocide, whether it's with the Uyghurs in China or the war in Ukraine," he said.

This article was updated on October 31, 2023.

Edited by: Davis VanOpdorp