António de Oliveira Salazar
Despite the authoritarian character of the regime, Portugal did not experience the same levels of international isolation as Spain did following World War II. Unlike Spain, Portugal under Salazar was accepted into the Marshall Plan (1947–1948) in return for the aid it gave to the Allies during the final stages of the war. Furthermore, also unlike Spain, it was one of the 12 founding members of the North Atlantic Treaty Organisation (NATO) in 1949, a reflection of Portugal's role as an ally against communism during the Cold War in spite of its status as the only non-democratic founder. In 1950, Portugal joined the European Payments Union and participated in the founding of the European Free Trade Association (EFTA) in 1960 and the Organisation for Economic Co-operation and Development in 1961. It joined the General Agreement on Tariffs and Trade in 1962, and finally, Portugal signed a free trade agreement with the European Economic Community in 1972, still under the auspices of the "Estado Novo".
Portugal–United Kingdom relations
Portugal was an official Allied Power in World War I; Portuguese troops were the first to be gassed by German soldiers, yet they received nothing after the Treaty of Versailles. In World War II, Prime Minister António de Oliveira Salazar was committed to the six-century-old treaty (which had been renewed in 1899). Portugal provided assistance not by declaring war but by helping Spain stay neutral and by assuming a co-belligerent status against Germany by leasing air bases in the Azores to the Allies in 1943. It cut off vital shipments of tungsten to Germany in 1944, after heavy Allied pressure. Lisbon was the base for International Red Cross operations aiding Allied POWs, and a main air transit point between Britain and the U.S.