Which act was established to unite the military forces of the United States and enhance national security in 1947?

The National Security Act of 1947 was a significant piece of legislation that aimed to reorganize and unify the military forces of the United States in the context of post-World War II security concerns. This act established the National Security Council to advise the President on security matters, and it created the Central Intelligence Agency (CIA), which centralized intelligence operations.

The establishment of the Department of Defense was also a key component, as it merged the Department of War and the Department of the Navy, ensuring a coordinated military strategy and better utilization of resources. The act reflected the need for a more integrated defense capability in the face of emerging global threats, particularly in light of the tensions of the Cold War.

This act laid the foundation for modern U.S. military and intelligence operations, ensuring that national security was not only a military concern but also included intelligence and strategic planning by various branches of the government. The choice correctly identifies the act that established these frameworks for enhancing national security.