What is considered genocide, and who gets to decide?

Genocide.

Both sides in the Israel-Hamas war have accused each other of intending to commit, or carrying out a campaign of genocide against their respective populations.

And, some human rights activists and watchdogs say they are seeing signs of genocide in the conflict.

South Africa has formally accused Israel of genocide in the International Court of Justice.

The application places Israel's genocidal acts and omissions within the broader context of Israel's 75-year apartheid.

But, what exactly is genocide?

How is it prosecuted in the international justice system?

And, what's the difference between the heated political rhetoric around genocide and these formal charges?

Genocide is thought of as the crime of crimes where you're actually trying to destroy the population, as such.

Leila Sadat served as a special advisor to the International Criminal Court prosecutor and is now with the Washington University Law School.

At the heart of any legal case for genocide is the 1948 convention established by the United Nations in the aftermath of World War II and the Holocaust.

The draft convention on genocide is being presented to the General Assembly today.

The codification in the convention itself really is a description of what happened during the Holocaust.

Subsequently, there was a hesitation to expand the use of this term because of its sort of symbolic importance as this was the crime of crimes.

But politicians and activists often use genocide in their rhetoric to draw attention to mass atrocities and war crimes.

The term has developed a weight and a political importance.

Kerry Whigham is with the Institute for Genocide and Mass Atrocity Prevention at Binghamton University.

It's really understandable that groups of people who are suffering mass atrocities, who are the victims of atrocities, often want the word genocide to be applied to what they're doing because it's a way of drawing political and social attention to the harms that they're suffering.

Whigham says the phrase itself has taken on new meaning outside of the international courts.

Whether or not a situation meets the legal definition of genocide, I think it's still important to pay attention to groups of people who are trying to use this term and have it applied to their case, because usually what it means is that they are experiencing large-scale identity based violence.

In the ICJ case of South Africa vs. Israel, South Africa is asking the ICJ to order Israel to stop its military action in Gaza.

Since both South Africa and Israel are U.N. member states and both are signatories to the 1948 genocide convention, they are obligated to not commit genocide and to also prevent and punish it.

It could take years to litigate the full case.

It's important to also note that the ICJ is not the only international court that can declare an act of war as genocide.

Unlike the ICJ, the International Criminal Court does not include every U.N. member state.

Instead, it's a treaty-based court.

Several major world powers, including the United States and Russia, are not state parties to the court and don't accept its jurisdiction.

But the bar is high to meet the legal definition for genocide, regardless of the court.

We know the law, it's the facts that are really hard to ascertain.

You have to prove a criminal case beyond a reasonable doubt.

And, in order to do that with respect to genocide, you have to show not only that the act was committed, you'd have to show one of the prohibited acts and that the accused actually committed that act with the intent to destroy the group in whole or in part.

But to some, using the word genocide to describe Israel's military campaign causes offense, given the terms origin.

Dov Waxman, the Rosalinde and Arthur Gilbert Foundation professor of Israel studies at UCLA, explains.

Accusing Israel, as a state, of conducting a genocide puts it effectively into the same company of perpetrators of genocide as Nazi Germany, for example, or the Hutus in Rwanda or Milosevic's regime in the case of the Serbian genocide, all of those previous instances which are widely recognized as genocide.

And for many, that is - not only does that delegitimize Israel itself by putting it into that company, but also Israel's legitimacy in the eyes of the world is itself tied to genocide, specifically to the Nazi genocide against Jews.

While the focus is on the term genocide, Whigham says, legally, there is no difference in terms of gravity when it comes to crimes against humanity, war crimes and genocide.

When people think about the Holocaust, they think about industrialized killing, they think about death camps, they think about gas chambers, and this industrialized plan to destroy groups.

That is not a requirement of genocide and, in fact, many genocides occur through the kinds of violence that we are seeing in Gaza right - and oftentimes in the case of Rwanda, it occurs from one person going up to another person and killing them with their own hands, looking at them in the eyes.

There are a whole host of other crimes, war crimes, for example, that Israel might be accused of committing, which may not amount to genocide, but is still very, very serious violations of international law.

To some extent, the focus on genocide is in danger of distracting attention from the broader issues of the violation of laws of war during the course of this conflict by both Israel and Hamas.

Whigham says understanding genocide as a long term social and political process is crucial to preventing it from happening in the first place.

There are actions that can be taken, both domestically and by the international community, to help impede them from escalating even further.

The problem is oftentimes we turn a blind eye to those earlier stages of genocide, and we only start paying attention when large scale violence is taking place.

And it's much, much harder to stop a genocide from happening when it's already reached that stage of active killing, of active destruction.

As the war rages on, so too will both the public and legal debate over the use and application of this term.

For the PBS NewsHour, I'm Deema Zein.