In joining the international criminal court, Mahmoud Abbas has finally used one of the most potent diplomatic weapons in the limited Palestinian armoury after years of unfulfilled threats. It is a gesture of near despair by a leader with little left to lose.

Signing the Rome statute opens up Palestinian territory to future ICC investigations, a situation which Israel fought a long and intense battle behind the scenes to avoid. It could one day put Israeli soldiers and officials in the dock of an international court for military operations and for the policy of building Israeli settlements on occupied Palestinian land.

ICC membership is a powerful weapon but it is also double-edged. It defines the geographical area in which such crimes can be investigated, and the Palestinian leadership could also define a time period for the prosecutors to examine, but it cannot dictate the target of such an investigation. For example, if Abbas now seeks a retroactive investigation of the last bloody bout of violence in Gaza last summer, as he has the right to do, both the Israel Defence Forces and Hamas would be scrutinised for their actions.

That was one reason for delay. Hamas is Abbas’s principal challenger on the Palestinian political scene, but he wanted to secure its approval before making a final decision on ICC membership. There were other reasons for caution. The threat of joining the court was also one of the few meaningful bargaining chips Abbas could take into the negotiating chamber with his Israeli counterpart, Binyamin Netanyahu. Now it has been used, he is virtually empty-handed. But such chips are only of any use when there is a dialogue and a diplomatic process. Right now, there is neither.

It is not the first time the Palestinians have sought redress at the ICC, which has been reluctant to get involved in the Israeli-Palestinian conflict. As long ago as 2009, they went to the court in The Hague with an ad hoc request for a war crimes investigation in the wake of an earlier Israeli offensive in Gaza, Operation Cast Lead. The chief prosecutor at the time, Luis Moreno Ocampo, took three years to decide on the status of that request before announcing in 2012 that it was a decision about Palestinian statehood that could only be taken by the UN general assembly. In November 2012, the UN voted to recognise Palestine as a non-member observer state, which gave it the right to join the ICC and make ad hoc requests for investigations. Moreno Ocampo’s successor as prosecutor, Fatou Bensouda, ruled that Palestine’s new status could not be applied to its 2009 request for an investigation. If the leadership wanted such an investigation, Bensouda argued, it would have submit the request again. But Abbas came under intense pressure from the Israelis, Americans, British and other Europeans not to do so, backed up by threats of financial and economic sanctions.

Wednesday’s decision will exact a price in the form of such punitive measures that could cripple the Palestinian Authority. But Abbas clearly decided he had been treading water for far too long. A fter the defeat on Tuesday of a UN security council resolution demanding an end to occupation by 2017, and with his popularity plummeting, he has sought to carve out as much Palestinian sovereignty as he can as a political legacy.

Under ICC rules, the Palestinians will have to wait 60 days from the signing of the Rome statute before filing cases at the court, but those two months come in the midst of an Israeli election campaign in which Netanyahu will seek to demonstrate a robust response to the Palestinian challenge.

Even once the 60-day waiting period is over, the UN security council has the power to stop ICC investigations from proceeding, and the prosecutor’s office can decide whether investigations should lead to indictments. Israel, the US and their allies can be expected to use all the lobbying power at their disposal to make sure Israeli soldiers and politicians are not indicted.

Acquiring ICC membership and satisfying Palestinians’ demands for justice could prove to be very different things.