Out of government during his so-called "wilderness years" in the 1930s, Churchill took the lead in calling for British rearmament to counter the growing threat of militarism in Nazi Germany. At the outbreak of the Second World War he was re-appointed First Lord of the Admiralty. In May 1940, he became Prime Minister, replacing Neville Chamberlain. Churchill oversaw British involvement in the Allied war effort against the Axis powers, resulting in victory in 1945. After the Conservatives' defeat in the 1945 general election, he became Leader of the Opposition. Amid the developing Cold War with the Soviet Union, he publicly warned of an "iron curtain" of Soviet influence in Europe and promoted European unity. He lost the 1950 election, but was returned to office the following year in the 1951 election. His second term was preoccupied with foreign affairs, especially Anglo-American relations and the preservation of the British Empire. Domestically, his government emphasised house-building and developed a nuclear weapon. In declining health, Churchill resigned as Prime Minister in 1955, although he remained an MP until 1964. Upon his death in 1965, he received a state funeral.