Watching diplomats from around the globe voting in 1998 to establish the world’s first permanent international criminal court, I allowed myself to believe that putting individuals on trial for crimes against humanity might deter future tyrants. Sadly, the International Criminal Court (ICC) has not lived up to the high hopes of its founders. Calling for an independent assessment of the court’s work last year, four former presidents of the assembly that represents the court’s member states said they were “disappointed by the quality of some of its judicial proceedings, frustrated by some of the results, and exasperated by the management deficiencies that prevent the court from living up to its full potential”.

When those states met in December, the UK said the need for change was now “acute and pressing”. Judges needed to be elected on the basis of “merit and experience”, the government added. And the new prosecutor, who takes over next year, should be “demonstrably the best, most qualified candidate”.

It was implicit that those criteria had not been met. The UK called for a review of how the court’s prosecutor was interpreting the “complementarity” test — which says the ICC should get involved only if a member state is unwilling or unable to bring criminal charges itself.

Those comments were aimed at Fatou Bensouda, the current prosecutor, who has now spent six years considering whether UK troops committed unpunished war crimes against detainees in Iraq between 2003 and 2009. Her concern is that UK investigators may be trying to shield British soldiers from criminal accountability. Foreign Office lawyers want her to concentrate on the big picture — Britain’s commitment to the rule of law — instead of trying to micromanage individual cases.

Early in 2015, Bensouda opened a preliminary examination into what she called the situation in Palestine. At the end of last year, she concluded that there were reasonable grounds for upgrading her preliminary examination into a formal investigation. She accuses the Israel Defence Forces of disproportionate attacks in the Gaza conflict of 2014 while Hamas and other Palestinian armed groups are accused of intentionally directing attacks against civilians. Israel is also accused of using lethal force near the Gaza border in 2018 and “transferring” its civilians into occupied territory.

To initiate a formal investigation on her own initiative, the prosecutor needs prior authorisation from a pre-trial chamber of three judges. That’s not required if a state which has accepted ICC jurisdiction asks the court to investigate conduct that occurred on its own territory. The Palestinian leader Mahmoud Abbas accepted the court’s jurisdiction in 2015. As a result, Bensouda considers that the ICC’s jurisdiction extends to the territory occupied by Israel in 1967 — by which she means Gaza and the West Bank, including East Jerusalem.

As the prosecutor acknowledges, this is disputed. “The Palestinian Authority does not govern Gaza,” she notes. “Moreover, the question of Palestine’s statehood under international law does not appear to have been definitively resolved.” So, before she launches her investigation, she wants the pre-trial chamber to confirm that the ICC has territorial jurisdiction.

Her submissions run to 112 pages — a tacit admission that the arguments are controversial. Despite taking almost five years to get this far, she expects the judges to rule on jurisdiction by late April. In a detailed opinion published hours before Bensouda’s announcement, Israel’s attorney general Avichai Mandelblit said that the ICC has no jurisdiction because Palestine is not a state under international law. A sovereign state has criminal jurisdiction over its nationals and those within its territory. But the Palestinian Authority has no such jurisdiction over Gaza, Jerusalem or Israeli settlements in the West Bank. If these areas are occupied, as the Palestinians claim, then jurisdiction must rest with the occupying power.

Speaking for the Israeli government, Mandelblit argued that the ICC operates on the basis of powers delegated to it by states parties. If no sovereign state has jurisdiction over a territory, no state can delegate jurisdiction to the court. Sovereignty over the West Bank and Gaza remains in abeyance pending peace negotiations.

Israel is not a party to the court’s founding treaty but, behind the scenes, its officials have been engaging with the prosecutor’s office. The Israelis argue that the ICC should concentrate its limited resources in areas where the facts and jurisdiction are beyond doubt. No court could possibly say it was a “serious violation of the laws of war” to let Jews return to the Jewish Quarter of Jerusalem in 1967, 19 years after they were expelled. But Ukraine is still waiting for the ICC to investigate Russia’s invasion and annexation of Crimea in 2014.

If the ICC had brought more warlords to justice over the past two decades, it might have earned the world’s respect. But prosecuting individuals cannot resolve international conflicts. It merely prolongs them.