The significance of the Cold War for international relations was profound, marking a period of ideological, political, and military tension between the United States and the Soviet Union from the late 1940s to the early 1990s. It established a bipolar world order where countries aligned with either capitalism or communism, influencing foreign policy globally. The arms race, space race, and proxy wars characterized this period, highlighting the threat of nuclear conflict. The Cold War also led to the establishment of military alliances like NATO and the Warsaw Pact, shaping diplomatic relationships and international politics for decades, and ultimately culminating in the dissolution of the Soviet Union.