The Palestinians have submitted documents requesting membership in the International Criminal Court. What do they hope to achieve?

First of all, the Rome Statute of the International Criminal Court must be ratified - it's the treaty that establishes the foundation for the court. That will probably happen over the next few days. The General Assembly has recognized Palestine as a state. In that respect, all legal hurdles should then be cleared. As a signatory state, Palestine could then file a lawsuit concerning a particular situation. That's to say a suit concerning a crime covered by the statute.

Why has the Rome Statute not been accepted by all countries?

That is due to fears that a country's own citizens might be prosecuted by the International Criminal Court - in accordance with the rule of law, of course. That's true in particular for the United States, which feels that such an international criminal authority is superfluous and could be misused for political purposes. For similar reasons, the same is true for China and Russia; neither has submitted to the jurisdiction of the International Criminal Court. In the end, accepting the Rome Statute would let the International Criminal Court monitor a country's policies. That's not something governments want to accept.

That's also the case for Israel, and the same time, the Palestinian request seems to put pressure on the Israeli government. Prime Minister Benjamin Netanyahu has retaliated with threats of a lawsuit against the Palestinian leadership. Is that even possible as long as Israel isn't a signatory member state of the International Criminal Court?

Israel would have to join first. The court's jurisdiction extends to the citizens of each of its signatory states, as well as to the crimes committed on member states' territory. Once Palestine is recognized as a signatory party, any severe crime committed on Palestinian territory, for instance by Israeli soldiers, would fall under the jurisdiction of the International Criminal Court. It would apply from the membership date onwards. It would have an impact on the future.

It doesn't apply to crimes committed in the past?

Certainly not. It's a fundamental principal of contract law that all rights that accrue from an agreement apply only upon ratification. But it's still something that could become an important political weapon for the Palestinians, including in negotiations with Israel. Whether it's wise to use this weapon, or whether it leads anywhere - that's quite another question.

Why?

You enter the realm of endless disagreement and difficulties. This is particularly the case when you're solving crimes where you have to collect evidence. It's very clear that the Israeli government feels put under pressure, and it won't be willing to make any concessions in negotiations.

On the Palestinian side, I would have first ratified the other international law treaties and human rights accords before taking that last step and joining the Rome Statute. Obviously, that increases tensions.

Professor Dr. Dr. h.c. Christian Tomuschat is emeritus professor of international law at Berlin's Humboldt University, a former member of the UN Human Rights Committee and a former member and head of the UN International Law Commission.