Actually, according to the United States Constitution, the power to declare war resides with the Congress, not the President. Article I, Section 8 grants the power to Congress to "declare War." This separation of powers ensures that the decision to engage in armed conflict is a collective decision made by the elected representatives of the people. While the President, as the Commander-in-Chief of the military, can deploy troops and take defensive actions to protect the nation, the authority to formally declare war requires Congressional approval.