Who has the power to declare war?

The correct choice is Congress, as this body holds the constitutional power to declare war according to Article I, Section 8 of the U.S. Constitution. This section specifies that Congress has the authority to declare war, which means that both chambers, the House of Representatives and the Senate, must agree to take such action.

While the President is the Commander in Chief of the armed forces and can take military action, the formal declaration of war is a power reserved for Congress. This division of power is a critical component of the checks and balances system established by the Constitution, ensuring that no single branch of government can unilaterally decide to engage in warfare. The roles of the President, the Senate, and the House are thus part of a larger framework designed to involve multiple layers of leadership in such significant decisions, promoting deliberation and consensus.