The BBC came out with a story a few days ago about how Major General (res.) Doron Almog, who was allegedly responsible for ordering the demolition of 50 houses in Gaza in 2002, managed to escape arrest in England. A British judge issued a warrant for his arrest and British police were primed to arrest him when he came to England in 2005. However, he was tipped off by the Israeli Embassy and refused to disembark the El Al plane. Fearing a confrontation with armed Israeli marshals, the British police let the El Al plane return to Israel without arresting Almog.
Hickman and Rose, the British law firm representing the Palestinians who brought the claim against Almog are outraged by the police's willingness to allow the plane to take off. They could have prevent Almog from leaving by denying the jet permission to return home. Yet not only did they allow Almog to leave, the British Foreign Minister at the time, Jack Straw, issued an apology for the incident.
Preventing these annoying confrontations is just one reason why universal jurisdiction is a bad idea. A number of countries, including Belgium, which almost tried sitting Prime Minister Ariel Sharon for war crimes, have a law that grants their courts jurisdiction over any person, anywhere who is responsible for committing war crimes, genocide or crimes against humanity (Belgium modified its law in 2003 because of the Sharon fiasco).
I'm not against the concept of universal jurisdiction in some cases. Certainly war crimes should be punished and some states don't have the capabilities to do so. But the prospect of political misfeasance outweighs the practical benefits of deterring actual war criminals and these applications of the universal jurisdiction statutes to Israeli leaders and generals is a prime example. Israel is a flourishing, albeit imperfect, democracy with an abundance of judicial review (perhaps too much). War crimes are taken seriously and cases can be brought in Israeli military or civil courts. Israel has been known to create commissions to review especially egregious examples, the Kahan Commission being the most famous example.
Foreign countries should not get involved when the alleged criminal lives in a country with a functioning judicial system that is serious about preventing crimes against humanity and war crimes. That is especially true about countries that are currently involved in a war itself and might have its own generals dragged into court in some other country. All countries should think long and hard about whether the benefits of these univeral jurisdiction statutes outweigh the costs.