Lee H. Hamilton

“...the Constitution is an invitation for the president and Congress to struggle for the privilege of directing foreign policy. Although the president is the principal foreign policy actor, the Constitution delegates more specific foreign policy powers to Congress than to the executive. It designates the president as commander-in-chief and head of the executive branch, whereas it gives Congress the power to declare war and the power of the purse. The president can negotiate treaties and nominate foreign policy officials, but the Senate must approve them. Congress is also granted the power to raise and support armies, establish rules on naturalization, regulate foreign commerce, and define and punish offenses on the high seas.

Although the president is the chief foreign policy maker, Congress has a responsibility to be both an informed critic and constructive partner of the president. The ideal established by the founders is neither for one branch to dominate nor for there to be an identity of views between them. Rather, the founders wisely sought to encourage a creative tension between the president and Congress that would produce policies that advance national interests and reflect the views of the American people. Sustained consultation between the president and Congress is the most important mechanism for fostering an effective foreign policy with broad support at home and respect and punch overseas. In a world of both danger and opportunity, we need such a foreign policy to advance our interests and values around the globe.”
― Lee H. Hamilton, A Creative Tension: The Foreign Policy Roles of the President and Congress