America's Foreign Policy Practice Exam 2025 – Comprehensive Test Prep

The event that exemplified the U.S.'s unilateral decision-making in war matters after World War II is the Korean War, where the decision to intervene was made without formal consultation with Congress. In June 1950, when North Korea invaded South Korea, President Harry S. Truman promptly committed U.S. forces to defend South Korea. This action was taken under the auspices of the United Nations, but it did not involve a formal declaration of war from Congress, which is a key aspect of unilateral decision-making. The military intervention signifies how the executive branch could act quickly in a crisis without legislative approval, reflecting a shift in the balance of power regarding war-making authority that took shape in the post-World War II era. The context of this decision also aligns with the broader Cold War mentality, where rapid responses to perceived threats were deemed necessary.

In contrast, the Vietnam War was characterized by significant Congressional involvement and eventual authorization through the Gulf of Tonkin Resolution, making it less of an illustration of unilateralism. World War II involved strong public support and an overall national consensus, which further complicates its relevance to the question of post-war unilateral decisions. The Gulf War, while grounded in coalition support and UN resolution, also involved careful international diplomacy rather than