In 1938 , who 's population was larger , The Western Allies or the European Axis ?
Canada , the United States , and the European countries among this group formed a military alliance called the North Atlantic Treaty Organization , or NATO , to oppose the Eastern Bloc and their military alliance , the Warsaw Pact , which was composed of the wartime Allies Poland , Czechoslovakia , and the Soviet Union , the ex-Axis powers of Bulgaria , East Germany , Hungary and Romania as well as Albania .