Guillermo Otálora Lozano [International Criminal Law Interest Group, American Society of International Law]: "The Italian rulings against Germany for crimes committed during the occupation reflect a growing trend in domestic courts' practice towards the lifting of immunities when international crimes are at stake. The ICJ has already dealt with issues of immunities in the Arrest Warrant (DRC v. Belgium) (2002) and Criminal Assistance (Djibouti v. France) (2008) cases. The first one upheld the personal immunities of a Congolese Minister of Foreign Affairs against charges of war crimes in Belgium, while the second one declined to do so in respect to the functional immunities of Djiboutian governmental staff (due to Djibouti's failure to claim immunity with respect to France in the first place). However, in both cases the same principle was explicitly or implicitly affirmed: a State may not be the judge of another State (par in parem non habet imperium). This is the same legal principle underlying the jurisdictional immunities of States, whose customary character was most recently confirmed by the 2004 UN Convention on the Jurisdictional Immunities of States and their Property [PDF file], and several decisions by domestic courts.
There is some case-law in support of an exception to this rule when it concerns international "core crimes" (genocide, war crimes, crimes against humanity, enforced disappearance, torture, and possibly aggression), including the Eichmann judgment by the Israeli Supreme Court, and the much-publicized Pinochet decision by the UK House of Lords in 1998. However, the jurisdictional immunities of States have also been upheld in such cases, for instance, by the European Court of Human Rights in the Al-Adsani v. United Kingdom case, and by the Canadian Supreme Court in Bouzari v. Iran.
In sum, there is contradictory authority on the issue, and there is no consensus among international scholars as to whether such an exception exists in international law. Germany's application represents a new opportunity for the World Court to do what it did not do in the 2002 Arrest Warrant case. However, policy concerns about this purported exception need to be taken into account. While ICJ judgments do not formally have the value of precedents (Article 59, ICJ Statute), they do have great effects on the formation of international law and practice. The 2002 judgment effectively shaped European policy with regard to universal jurisdiction. These proceedings, if continued towards a final judgment, could either boost or trample on the nascent customary exception to State immunities in cases of international crimes. This suit is thus not only about World War II atrocities, but the handling of individual claims for redress for more recent crimes or alleged crimes.
The humanitarian appeal of lifting immunities in these cases is evident, but a decision upholding an exception to sovereign immunity in these cases could well create more problems than it would purportedly solve. It could create an incentive for States to take matters into their own hands by exercising their jurisdiction against other States, instead of bringing claims for responsibility before the proper international forum, and undermine the international rule of law which the advocates of this exception seek to establish."