Question

The power to declare war is

Answer 1

The short answer is that the Constitution clearly grants the Congress the power to declare war, in Article 1, Section 8. This power is not shared with anyone, including the President. The President, however, is just as clearly made the Commander in Chief of all of the armed forces, in Article 2, Section 2.

Source: http://www.usconstitution.net/constfaq_q108.html