Since the beginning of the Republic, Presidents have addressed sensitive and high-profile matters in negotiations that culminate in commitments, both binding and non-binding, that Congress does not approve. Under Presidents of both parties, such major shifts in American foreign policy as diplomatic recognition of the People’s Republic of China, the resolution of the Iran hostage crisis, and the conclusion of the Vietnam War were all conducted without Congressional approval.

In thirty-six years in the United States Senate, I cannot recall another instance in which Senators wrote directly to advise another country—much less a longtime foreign adversary— that the President does not have the constitutional authority to reach a meaningful understanding with them. This letter sends a highly misleading signal to friend and foe alike that that our Commander-in-Chief cannot deliver on America’s commitments—a message that is as false as it is dangerous.

The decision to undercut our President and circumvent our constitutional system offends me as a matter of principle. As a matter of policy, the letter and its authors have also offered no viable alternative to the diplomatic resolution with Iran that their letter seeks to undermine.