The International Criminal Court this week announced it will begin an investigation into war crimes allegedly committed by Israel and Palestinian militants since 2014, which could theoretically put senior figures on both sides in the dock at the Hague.
Fatou Bensouda, the ICC’s chief prosecutor, has described the process as “daunting and complex” because it will be launched during a global pandemic, signalling that the investigation and any trial which follows could drag on for many years.
Israel has condemned the ICC’s decision as “pure anti-semitism,” while Palestinian leaders and human rights groups say that a war crimes probe is long overdue.
Here we look at the key allegations over war crimes, the possible timeline for the ICC process and what penalties could be imposed in the event of a guilty verdict.
How did we get here?
The ICC has powers to prosecute those accused of crimes against humanity, genocide, and war crimes in the territories of the court's members.
Back in December 2019, the ICC said that after a “thorough” investigation it had sufficient grounds to investigate both Israel and Palestinian militants over allegations of war crimes.
Ms Bensouda, the ICC chief prosecutor, then asked senior judges at the court to make a ruling on whether it had jurisdiction over the Palestinian territories of Gaza and the West Bank.
This was contentious in Israel. The Jewish state is not a member of the ICC and it disputes the Palestinians’ membership of the court, on the grounds that there is no Palestinian state.
On February 5 of this year, the ICC’s senior judges ruled that the court did have jurisdiction over the Palestinian territories, which was followed by prosecutors formally announcing a war crimes probe on March 2.
Which alleged war crimes will be investigated?
The allegations can be broadly defined as four separate cases. The first relates to war crimes allegedly committed by the Israel Defence Forces (IDF) in the 2014 Gaza conflict.
According to the United Nations, the 50-day war led to the deaths of 2,104 Palestinians, including 1,462 civilians.
The second case relates to the Palestinian Islamist faction Hamas, among other Palestinian armed groups, which are also alleged to have committed war crimes. They include the killings of civilians, torture and the use of so-called human shields.
The third and fourth cases relate to the activity of Israeli settlements in the West Bank - which are widely regarded as illegal under international law - and allegations of Israeli soldiers using “non-lethal and lethal means” against Palestinian protesters at the Gaza fence in 2018.
How has Israel responded?
Both sides deny committing war crimes. Benjamin Netanyahu, the Israeli prime minister, has branded the ICC probe “absurd” and an “attack” on the state of Israel.
Israeli officials say the investigation would be a severe misuse of resources, arguing that the real war crimes that should be investigated are taking place in Syria under dictator Bashar al-Assad. They also say that the ICC is trying to punish Israel for defending its people against terrorist threats.
Mr Netanyahu is said to be putting diplomatic pressure on his allies, such as the United States, to resist the court’s investigation.
He will have been heartened by Washington’s response to the ICC in February when it accused prosecutors of targeting Israel “unfairly.”
The ICC strongly denies charges of bias and says it conducts investigations “independently, impartially and objectively, without fear or favour.”
And the Palestinians?
Meanwhile Palestinian leaders, who asked the ICC to look at the allegations surrounding the Gaza war, have praised the investigation.
A Palestinian foreign affairs ministry spokesman said the investigation was a “long-awaited step that serves Palestine’s tireless pursuit of justice and accountability.”
Hamas has also welcomed the investigation, even though it will examine the actions of its own forces.
Human rights groups such as Amnesty International have also welcomed the probe.
“This is a momentous breakthrough for justice after decades of non-accountability for war crimes and crimes against humanity,” said Matthew Cannock, the head of Amnesty’s international justice department.
What happens next and how long will this take?
The court is now in the process of gathering evidence for all four cases and will eventually begin issuing subpoenas and arrest warrants for suspects.
Daniel Reisner, the former head of the IDF’s international law department, said the court will be seeking some of the most senior figures in the military.
“Theoretically, what happens is that when the court launches an investigation, at some point in time they create a list of the people they want to subpoena,” he said in a briefing at the Jerusalem Press Club.
He added: “The prosecutor pointed out they only go after the most infamous potential criminals. In general, they don’t go for the small fry. Who will they go for? High-ranking soldiers and politicians.”
According to Israeli media reports, senior security figures may be advised not to travel abroad to minimise their risk of being arrested.
One public figure who may be targeted by the court is Benny Gantz, the Israeli defence minister who was military chief of staff in 2014. He strongly denies any wrongdoing.
It is difficult to predict how long the investigation will last, but it is likely to be a question of years rather than months.
Israel and Hamas have both made it clear they would not be entering guilty pleas in the event of a trial, which would have cut down the duration of proceedings.
Ms Bensouda's term as chief prosecutor is due to end in June, when she will be succeeded by British prosecutor Karim Khan, who is expected by human rights groups to "pick up the baton".
If found guilty, how would any war criminals be sentenced?
If a trial goes ahead, prosecutors would need to prove beyond all reasonable doubt that a war crime has been committed. If the case fails to meet that high burden of proof, then the defendants are released.
If the accused are found guilty, ICC judges have powers to impose prison sentences of up to 30 years. In exceptional circumstances, the court can also impose life sentences.
But the ICC’s process is still at a relatively early stage; it must first carefully examine troves of evidence spanning seven years of the world’s oldest conflict before it enters the trial phase.