Time for a primer on international agreements, thanks to the controversy over Senator Tom Cotton’s letter to Iran.

Joined by almost all Republican senators, the missive warned Tehran that any nuclear deal with President Obama would not last unless it went to Congress for approval:

We will consider any agreement regarding your nuclear-weapons program that is not approved by the Congress as nothing more than an executive agreement between President Obama and Ayatollah Khamenei. The next president could revoke such an executive agreement with the stroke of a pen and future Congresses could modify the terms of the agreement at any time.



As a description of American constitutional law, Senator Cotton has it exactly right. It was as if he were just informing Iran about the text of the Constitution. There are three types of international agreements under U.S. law:

a. Treaties: These require two-thirds of the Senate for approval. The U.S. has generally used treaties for the most serious commitments of American sovereignty, such as alliances and arms control.

b. Congressional-Executive agreements: These require approval by the House and the Senate. Although unmentioned in the Constitution, they are nothing more than regular laws passed by Congress. These have been used for deals such as trade agreements.

c. Sole executive agreements: These are made by the president alone. They are constitutional only because they represent promises by the president on how to exercise his constitutional power.

The Cotton letter is right, because if President Obama strikes a nuclear deal with Iran using only instrument (c), he is only committing to refrain from exercising his executive power — i.e., by not attacking Iran or by lifting sanctions under power delegated by Congress. Not only could the next president terminate the agreement; Obama himself could terminate the deal.

In fact, the Cotton letter could have gone farther and pointed out that Obama may make promises that he cannot keep. Since a sole executive agreement is only a commitment for the use of the executive’s authority, it cannot make promises about Congress. Under the Constitution’s Foreign Commerce Clause, only Congress has the authority to impose international economic sanctions. Obama’s executive agreement cannot prevent Congress from imposing mandatory, severe sanctions on Iran without the possibility of presidential waiver (my preferred solution for handling the Iranian nuclear crisis right now). Obama can agree to allow Iran to keep a nuclear-processing capability; Congress can cut Iran out of the world trading and financial system.



Doubts can be raised about the diplomatic wisdom of the letter. The United States has long sought, ideally, to treat the president as “the sole organ” of its foreign policy, though in reality Congress has dominated foreign policy for periods of American history. Centralization of diplomacy in the president has been thought to prevent foreign nations from manipulating our branches against each other, though students of bargaining — or anyone who has to haggle over the price of a car with a salesman and his mysterious manager — will understand that having to overcome a subsequent Senate veto could result in a better deal for the U.S.

But as a matter of constitutional law, the Cotton letter should be no more controversial than a letter that simply enclosed a copy of the U.S. Constitution (without President Obama’s editing).


For those who want a fuller treatment, John Bolton and I went through the implications of this for the Iranian deal in the December 31, 2014, issue of NR.

For those who want to delve more deeply into the constitutional history and game theory of these international agreements, I’ve written the most recent (and I think one of the better) scholarly law articles on the subject (free download).