The always interesting, often depressing Opinio Juris blawg is reporting that a suit against former US Secretary of Defense Donald Rumsfeld has been halted due to Rumsfeld's supposed immunity.
Make no mistake, folks, this is Bad News. One of the biggest advances in international law has been the erosion of immunity against prosecution for very serious crimes against human rights or humanitarian law. To quote the meat of Kevin Jon Heller's post:
That said, there is no question that Rumsfeld is not entitled to immunity from prosecution for acts of torture. However unsettled the law of immunity might be, it is at least clear that functional immunity — immunity ratione materiae — does not preclude a government official from being prosecuted for serious international crimes. The House of Lords specifically held in Pinochet #3 that Pinochet was not immune from prosecution for acts of torture, and Robert Cryer, Hakan Friman, and Daryl Robinson have pointed out — in their excellent new book An Introduction to International Criminal Law and Procedure — that "out of all the international crimes cases that have been conducted to date, most of the defendants were acting on behalf of a State and yet not one has successfully pleaded functional immunity for international crimes."
A commenter points to the Yerodia case as an ICJ ruling upholding immunity, but my reading of that case (which admittedly may be faulty) was that they were upholding the immunity of currently-serving public officials whose immunity was important to functioning government (in that case, a Foreign Minister). Since Runsfeld left office in 2006, he would appear to be a legitimate target.