The Gulf of Tonkin Resolution granted broad authority to the President to use military force in Southeast Asia without a formal declaration of war.

• A. War Powers Act
• B. North Atlantic Treaty
• C. Gulf of Tonkin Resolution
• D. Marshall Plan

Answer: (C)

The question is about how Congress can authorize the president to use military force without a formal war declaration. The Gulf of Tonkin Resolution did exactly that in 1964, after the Gulf of Tonkin incidents. It gave the president broad authority to take all necessary measures to defend Southeast Asia and to repel aggression, effectively letting the United States escalate its involvement in Vietnam without Congress issuing a formal declaration of war.

This differs from a formal declaration of war, which is a clear, official act of Congress declaring war, rather than a broad authorization to use force. Later on, the War Powers Act tried to curb this kind of power by setting time limits and requiring reporting, while NATO is a defense alliance and the Marshall Plan was economic aid, not a presidential authorization to wage war.