Which alliance is the collective defense treaty formed during the Cold War that included the United States, Canada, and Western European nations?

• A. Warsaw Pact
• B. ANZUS
• C. OAS
• D. NATO

Answer: (D)

This question tests your understanding of postwar defense alliances and which one linked the United States, Canada, and Western Europe. NATO, the North Atlantic Treaty Organization, fits this description. It was established in 1949 to coordinate and commit collective defense among member nations, with the idea that an armed attack against one would be treated as an attack against all. This created a united front against potential aggression from the Soviet Union and its allies, helping to shape security in Western Europe during the Cold War. The alliance started with the United States, Canada, and Western European countries and grew over time. The other options point to different groupings: the Warsaw Pact was the Soviet-led alliance of Eastern Bloc countries, ANZUS is a security pact among the United States, Australia, and New Zealand, and the Organization of American States operates within the Americas rather than across North Atlantic Europe.