Palme, Olof (Sven Olof Joachim Palme)ōˈlôf pälˈmə, 1927–86, Swedish political leader, prime minister of Sweden (1969–76, 1982–86). Palme joined the Social Democratic party in 1952, entering parliament shortly afterward. Serving (1954–63) as private secretary and counsel to Prime Minister Tage Erlander, he later held several ministerial posts. In 1969, Palme succeeded Erlander as chairman of the Social Democratic party and prime minister. In 1971, Palme led Sweden's rejection of a bid for membership in the European Community as not compatible with a policy of Swedish neutrality. Although the 1973 general election resulted in a tie in the Riksdag between Palme's Social Democrats and the nonsocialist bloc, the prime minister remained in office. In foreign affairs, Palme's criticism of U.S. policy in Indochina led to a diplomatic rift with the United States, which ended in 1974. Palme also opposed the nuclear arms race and South African apartheid and championed the Palestine Liberation Organization and Castro's Cuba. He was assassinated in 1986; the killer has not been identified.