In Europe, the conflict between the Soviet Union and the Western Allies grew into the Cold War. In July 1949, the United States approved the North Atlantic Treaty. "It" joined with Canada and ten nations of Western Europe in promising a common defense against aggression for 20 years. 에서 "It"이 가리키는 게 The North Atlantic Treaty / the United States 중 어떤건가요?해설도 같이 도와주세요..ㅠ
