History of NATO
The history of the North Atlantic Treaty Organization (NATO) begins in the immediate aftermath of World War II. In 1947, the United Kingdom and France signed the Treaty of Dunkirk and the United States set out the Truman Doctrine, the former to defend against a potential German attack and the latter to counter Soviet expansion. The Treaty of Dunkirk was expanded in 1948 with the Treaty of Brussels to add the three Benelux countries (Belgium, the Netherlands, and Luxembourg) and committed them to collective defense against an armed attack for fifty years.