US President Joe Biden has levelled an accusation of genocide against Russia in relation to its war in Ukraine.
The word carries a certain gravity — it's widely considered one of the worst atrocities imaginable, the "crime of all crimes".
However, simply saying "genocide" has occurred and proving it in a court of international law are two different things.
So what is the significance of the US President escalating the rhetoric?
What exactly did Biden say?
His declaration was made in an unlikely place: during a speech in Iowa about fuel prices.
"Your family budget, your ability to fill up your tank, none of it should hinge on whether a dictator declares war and commits genocide a half a world away," Mr Biden said.
He later doubled-down as he prepared to board Air Force One.
"Yes, I called it 'genocide' because it has become clearer and clearer that Putin is just trying to wipe out the idea of being able to be Ukrainian and the evidence is mounting," he said.
What is genocide?
The Genocide Convention was the first human rights treaty to be adopted at the UN General Assembly in 1948, and it came to signify the promise of "never again" after the Holocaust.
Legally, genocide includes five acts committed with the "intent to destroy, in whole or in part, a national, ethnical, racial or religious group", according to the UN.
Those acts include:
- killing members of the group
- causing them serious bodily or mental harm
- deliberately inflicting conditions of life calculated to bring about the group's physical destruction in whole or in part
- imposing measures intended to prevent births within the group
- forcibly transferring children of the group to another group.
Leila Sadat, an expert on war crimes and international law at Washington University in St Louis, told National Public Radio the crime requires proof of intent.
"We are definitely seeing evidence of crimes against humanity and war crimes," she said.
"Genocide requires this special intent, so we actually have to show that they're committing all these terrible crimes in order to destroy, in part or in whole, the particular group."
How significant is the 'G-word'?
Dr Ángel Alcalde — a lecturer in history at the University of Melbourne — said such a declaration can shape international public opinion, but can also have legal consequences.
"Politically, it is very significant to invoke the concept of 'genocide', not just because of the meanings attached to this notion, but also because of the legal obligations for states under the United Nations Genocide Convention," he said, adding the US, Ukraine and Russia are signatories to the convention.
"Governments in the past, including the US government, have been wary of employing the 'G-word' at all when describing events of such nature precisely because of the potential legal implications of doing so."
Since the end of the Cold War, the US State Department has formally used the term just seven times.
These were to describe massacres in Bosnia, Rwanda, Iraq and Darfur, as well as in relation to the Islamic State's attacks on Yazidis and other minorities, China's treatment of Uyghurs and other Muslims, and the Myanmar army's persecution of the Rohingya minority. China denies the genocide claims.
Dr Eyal Mayroz — a senior lecturer at the University of Sydney's department of peace and conflict studies — has researched when the US has chosen to use the word genocide and when it has chosen to ignore it.
"Many different administrations were very shy and refused to use that terminology on a host of genocides during the Cold War," he said.
However, he said, it has become more common in recent years, after legal advisers to the US State Department changed their advice.
"They decided that you could refer the genocide label to a case without the US having to commit to anything," he said.
"A political determination has a lot less power than a legal determination, but it can be made much quicker. And, usually, a political determination is made for either domestic consumption or political gain."
What could be considered genocide?
Genocide expert Dr Alex Hinton said "there seems to be new evidence emerging every day that suggests genocide is taking place", referring to alleged executions in Bucha, the bombing of a train station, and the siege of Mariupol.
"What has been striking from the start of Russia's invasion is that genocidal intent, which is always hard to find, was openly articulated by Putin not just in speeches but in a long essay he wrote," he said.
"So the ideology driving the conflict had genocidal overtones from the start.
"Now we are seeing various acts that appear to match the rhetoric: massacres, rapes, deportations and so forth."
Reports of rape allegedly committed by Russian troops against Ukrainian civilians could be considered genocide in certain circumstances.
Dr Alcalde is researching sexual violence in wartime and the relationship between war and genocide.
"Whereas not all forms of sexual violence in wartime can be considered acts of genocide, if these acts are committed with the objective or motivation of causing the physical, cultural or social death of the victims, or of damaging the reproductive health of a group, they could be considered acts of genocide or ethnic cleansing," he said.
"Some of the recent reports from Ukraine would, indeed, reflect these kind of motivations."
Proving it could take years
Getting sufficient evidence to proceed with charges can be complex and time-consuming.
For example, the Khmer Rouge's mass killings in Cambodia were described as "genocide" for decades, but senior leaders were only convicted of the specific crime in 2018 — and only against the Vietnamese and Cham Muslims in Cambodia, not against the broader population.
Dr Alcalde said that, "to prove allegations of 'genocide' to the standards of proof and legal procedure of International Tribunals, may take many years".
The International Criminal Court (ICC) — which deals with criminal cases against individuals — has already opened an investigation into the situation in Ukraine.
"Is the motive to destroy the Ukrainian people, as a national group, in whole or in part as such? That will be the question that the court will have to decide on, and that will take a long time," Dr Mayroz said.
Moscow, in fact, used genocide as a justification for the invasion of Ukraine, which it calls a “special military operation”.
The International Court of Justice (ICJ), which deals with states, in March issued Russia a provisional order to “immediately suspend military operations” in Ukraine, saying it had not seen evidence supporting Russia’s allegation that Ukraine was committing genocide against Russian speakers in the eastern regions.
'Those victims need help now'
Dr Mayroz said while genocide often seen as the most severe crime, there was no hierarchy in international law that said it was worse than other crimes against humanity.
"We've seen some of the worst man-made tragedies in the world falling, not under genocide, but under crimes against humanity and war crimes," he said.
"Does it mean that the 8,000 people in Bosnia being killed for genocide is worse than 100,000 people in Nagasaki or Hiroshima?
"We should not let a so-called genocide debate undermine the importance and the call for immediate actions.
"Those victims need help now. And whether this is a genocide or crimes against humanity or war crimes is immaterial, what needs to be done is to act now."
ABC/Reuters
