The document outlines the key alliances and policies during the Cold War. The Soviet Bloc included Eastern European countries allied with the Soviet Union, while the Western Bloc comprised Western European allies of the United States. The Truman Doctrine of 1947 established the policy of US aid to countries threatened by communist takeovers, and containment was the overall Western strategy of containing the spread of communism. In response, the Eastern and Western Blocs each formed military alliances through the Warsaw Pact and NATO, respectively. The Iron Curtain divided Europe between Eastern and Western spheres of influence. Some non-aligned countries accepted investments from both sides. Later, treaties aimed to limit nuclear proliferation to five countries and establish inspections through the IAEA