The Court of Cassation stated that the Italian Ministry of Defense bears a substitutive responsibility for damages caused to the wife of a US member of the NATO Forces in consequence of a wrong medical treatment carried out in Italy at an US hospital; and this in application of Article VIII.5 of the 1951 Agreement between the Parties to the North Atlantic Treaty regarding the Status of their Forces. The decision was founded on the fact that, contrary to the allegation of the Ministry of Defense, the obligation to pay damages was not a contractual obligation (to which Article VIII.5 does not apply). The Court specified that the national courts must interpret treaties in accordance with Articles 31 to 33 of the Vienna Convention on the Law of Treaties, and not by making recourse to principles on interpretation resulting from national law.