The North Atlantic Treaty Organization began in 1949 as a bulwark against the Soviet Union, but has expanded in size in the decades since The North Atlantic Treaty Organization began in 1949 as a bulwark against the Soviet Union, but has expanded in size in the decades since The North Atlantic Treaty Organization (Nato) was created at the outset of the cold war, with its founding aims to act as a bulwark against the Soviet Union and guarantee the security of its members through political and