Italy adopts Supreme Court's view of ICJ authority
In a series of decisions in last decade—Sanchez-Llamas v. Oregon and Medellin v. Texas the Supreme Court effectively left the U.S. free to ignore decisions of the International Court of Justice, even when it had accepted the ICJ's jurisdiction. The Court ruled that the ICJ's interpretations of treaties are not binding on U.S. courts, and that compliance with international law does not override domestic constitutional principles, or even matters of criminal procedure.
It is hard to overstate the ridicule these decisions attracted from wide swaths the academy, international lawyers, and so forth. The Supreme Court was portrayed as a parochial international scofflaw. The decisions were said to be ugly examples of American exceptionalism that would alienate America from the "world."
Now the Italian Constitutional Court has followed suit, refusing to apply a decision of the ICJ, and doing so on even stronger grounds.
In the last decade, several Italian courts awarded damages against Germany to victims of war crimes during the Nazi occupation of Italy in 1944. These rulings contradicted the basic principle of sovereign immunity, and on that basis Germany sued Italy at the ICJ.
In 2012, the ICJ ruled in Jurisdictional Immunities of States (Germany v. Italy) that state immunity applies even to serious human rights violations. The decision was hardly surprising given prior immunity rulings.
However, the Constitutional Court in Rome ruled that Italy cannot follow the ICJ's judgement. For the Italian court's opinion, I rely on this summary. For an extended, baroque discussion of the Italian case by a European academic can be found here (note his description of the Medellin cases as "retrograde proclamations of provinciality.")
The Constitutional Court was required to reject the ICJ on even broader and stronger grounds did SCOTUS. Medellin v. Texas was based largely on the "dualist" principle of interpretation that international law has no direct effect domestically unless given such by statute. In this regard a judgement of the ICJ would just be like most treaties, which are not directly enforceable.
Italy, however, has the opposite of a dualist system: it has a constitutional provision directly incorporating international law (as do many other countries). So it could not simply say the ICJ decision has no direct effect. Rather, it went further to say that the rule announced by the ICJ itself violates the Italian constitution.
The constitutional argument seems to be a rather thin one, based less on specific words than on the general notion of no right without a remedy. Of course, Italy recognizes other immunities and limitations on suit, but given the crimes involved here, immunity would be "disproportionate." It seems like a lot of hand-waving, but on this reasoning the Italian court concluded the Constitution precludes listening to the ICJ (presumably the constitutional principle of proportionality trumps the explicit provision about incorporation of international law).
Finally, in a move that would bring joy to Sen. Bricker, the Italian court held by extension that the U.N. Charter, which requires compliance with the ICJ's orders, is unconstitutional as applied.
Whatever one can say about Medellin now, it will be hard to call it American exceptionalism. Indeed, it may be part of what internationalist commentators like the most—a "global judicial dialogue," in which Europe is beginning to listen to America. And that is what the internationalist motto of a "decent respect for the opinions of mankind" is really about.