 The United States and Cuba concluded a Treaty of Relations in 1934 which, among other things, continued the 1903 agreements that leased the Guantanamo Bay Naval Base to the United States.In 1959 Fidel Castro's 26th of July Movement overthrew the government of Fulgencio Batista and Batista fled the country on January 1, 1959.Relations between the United States and Cuba deteriorated rapidly as the Cuban government expropriated US properties and developed close ties with the Soviet Union.