Switzerland was a base for espionage by both sides in the conflict and often mediated communications between the Axis and Allied powers by serving as a protecting power. In 1942, the United States Office of Strategic Services (OSS) was established in Bern. Through the efforts of Allen Dulles, the first US intelligence service in Western Europe was created. During the allied invasion of Italy, the OSS in Switzerland guided tactical efforts for the take-over of Salerno and the islands of Corsica and Sardinia.