Ever wonder why the US has a naval base in a Communist country? In 1898, during the Spanish-American War, the US invaded Guantánamo Bay, Cuba, and later decided to build a military base there. In 1903, it signed a treaty to lease perpetually 45 square miles of land for $2,000 in gold coins per year. In 1934, the lease was modified to allow the payment to be made in US dollars and to say that the treaty could be ended only by the joint consent of the governments of Cuba and the US - or if the US abandoned the property. Since Fidel Castro came to power in 1959, relations between the two nations have been rocky, but the base remains.
Sources: 'The Explainer' (Anchor Books); US Navy