Germany warned Monday of severe consequences should its immunity as a state be breached if the UN\'s highest court allows Italian civil courts to rule on compensation for Nazi war crimes. \"The consequences would be severe,\" the director-general for legal affairs in Germany\'s foreign ministry, Susanne Wasum-Rainer, told judges of the International Court of Justice in the Hague. \"Once state immunity has been perforated, there is no reason not to extend the exceptions to a range of other areas,\" she told the 16-judge bench. Germany and Italy are arguing their cases before the ICJ this week, after Berlin in December 2008 filed an application to ask the court to order Rome to stop its courts from hearing compensation claims for Third Reich war crimes. Wasum-Rainer said the whole system of victim compensation since World War II \"would be put into question and and opened to challenge before domestic courts.\" \"All inter-state peace settlements concluded after an armed conflict will be put into jeopardy by allowing domestic courts to re-examine and reopen them,\" she warned. If domestic courts could rule on foreign states, she added, \"plaintiffs would shop around for the most favourable national courts.\" Germany said that in allowing claims for abuses which happened between September 1943 and May 1945, Italy \"failed to respect the jurisdictional immunity\" that modern-day Germany enjoys under international law. Third Reich troops committed war crimes after Italy switched sides to the Allies in September 1943, including in the case of Luigi Ferrini, who was deported to Germany as a forced labourer in August 1944, court documents said. Since an Italian Supreme Court decision in 2004 in his favour, numerous other claims by relatives and widows of victims of such crimes have been brought before Italian courts. \"There are currently about 80 cases pending with 500 plaintiffs,\" said Wasum-Rainer. Italian courts in turn have argued that the cases were admissible because abuses committed by German troops amounted to \"international crimes\" which took precedence over state immunity. \"Thus both our governments, Italian and German, are of the view that only an authoritative finding of this court will lead out of an impasse and will help to clarify this complex issue,\" Wasum-Rainer said. Also before the ICJ is Greece, because relatives of victims of a 1944 German massacre of Greeks at Distomo, in Greece, which claimed 218 lives, turned to the Italian courts after their case stalled in Athens. \"We are here because we want to find our right to justice. We hope for a positive outcome for Italy. Germany must respect the decisions taken in Italian courts,\" Vassilis Karkoulias of the Hellenic Association for Victims during the Time of German Occupation told AFP. In 1997 a Greek court ordered Germany to pay 28.6 million euros ($37 million) to the Distomo plaintiffs, but opposition from Berlin and reluctance from Greek justice ministers meant the ruling was never enforced. An Italian court however enforced the original ruling and slapped a financial charge on two buildings owned by the German state. Greece is taking part as a non-party state in the hearings which last till Friday, when judges will retire to make decision. Established in 1945, the ICJ is the UN\'s highest judicial organ and settles disputes between states. It is the only one of the six main UN bodies not located in New York.