Why did Congress pass the War Powers Resolution?

to allow the president to negotiate treaties
to allow the president to appoint the secretary of defense
to limit the president's power to appoint ambassadors
to limit the president's ability to send troops into combat

to limit the president's ability to send troops into combat

The primary purpose of the War Powers Resolution, passed by Congress in 1973, was to limit the president's ability to send troops into combat without congressional approval. It was sparked by concerns over the Vietnam War and the perceived misuse of presidential power in committing U.S. forces to military action without explicit consent from Congress. The resolution sought to provide a framework for the president and Congress to share responsibility in decisions regarding the deployment of military forces. It requires the president to report to Congress within 48 hours of committing armed forces to combat and sets a 60-day limit on unauthorized deployments, with a possible extension of 30 days for troop withdrawal. If Congress does not authorize the use of military force or conflicts continue beyond the time limits, it provides a mechanism for Congress to compel the withdrawal of forces.