Until World War II Iceland had very little contact with the United States. Because of the strategic importance of Iceland to the war in Europe The US and Iceland signed a treaty in June 1941. The Americans built military bases on land provided by Iceland. Construction on the airport began on 2 July 1942. It was occupied by US troops on 24 March 1943 and named Meeks field. After the war the US wanted to keep their bases but the Icelandic government said no. Ownership of Keflavik airport was returned to Iceland while the American military turned over their facilities to an American company to run for them. When Iceland joined the North Atlantic Treaty Organization in 1949, they sided firmly with the Americans in the Cold War. In 1951 a new treaty was signed and the American military returned to Iceland. During the cold war the Icelandic bases were used for surveillance in the North Atlantic. In the 1990s, with the end of the cold war, the US scaled back its operations in Iceland. In 2006 it closed down its base at Keflavik. 