[Cross-posted at Lawfare.]

In Marty’s post yesterday about the letter that 47 Senators sent to “the Leaders of the Islamic Republic of Iran,” he briefly addressed the question of “whether the President has the constitutional authority to complete the agreement in question without further congressional involvement.”  The answer to that legal question depends, he wrote, “largely on what specific obligations the agreement will impose upon the United States — something that virtually no one in this public debate has any knowledge of, by the way — and on how the agreement comports with historical sole-executive-agreement practice.”

That answer was right, as far as it goes, but it was incomplete.  Marty’s response to the constitutional question—like most other analysis on legal blogs—was based on the assumption that the deal being negotiated by the five permanent members of the UN Security Council, Germany and Iran would be an agreement that imposes obligations on the parties that are binding as a matter of international law.  That is certainly what the Senators’ letter itself suggested (it discusses “the [constitutional] power to make binding international agreements”).  And the response of Iran’s Foreign Minister Javad Zarif to the Senators was designed to leave the same impression:  Zarif referred to “international obligations undertaken by [the Obama Administration] in a possible agreement about Iran`s peaceful nuclear program,” and stated that “if the next administration revokes any agreement with the stroke of a pen, as [the Senators suggest it might], it will have simply committed a blatant violation of international law.”

Jack noted yesterday that this line of argument by Foreign Minister Zarif “prejudge[s] the question whether any Executive agreement between President Obama and Iran will in fact be a binding legal agreement under international law.”  And, later in the day, we were both struck by the way in which Vice President Biden, in his response to the Senators, chose to describe the history of “international commitments” undertaken by the United States that have “take[n] effect without Congressional approval.”  “Since the beginning of the Republic,” wrote the Vice President, “Presidents have addressed sensitive and high-profile matters in negotiations that culminate in commitments, both binding and non-binding, that Congress does not approve.”  And it was noteworthy that some of the examples the Vice President offered—such as the recent U.S.-Russia framework to remove chemical weapons from Syria, the diplomatic recognition of the People’s Republic of China, and “the conclusion of the Vietnam War”—were the result of nonbinding agreements, i.e., agreements, or “political commitments,” that do not impose obligations under international law.

There is little doubt that the President can agree to such nonbinding arrangements without congressional or Senate approval.  It has happened very frequently in our history, on matters both large and small.  (See pages 563-566 of this article by Duncan Hollis and Joshua Newcomer.  For helpful further background on such “soft law” agreements, or “political commitments,” see this recent article by Jean Galbraith and David Zaring.)  An example of a legally binding executive agreement is the Algiers Accords; an example of a non-legally binding executive agreement is the recent U.S.-China Joint Announcement on Climate Change.  Both types of agreement can express commitments and induce compliance based upon the logic of the agreement and the traditional, expected incentives associated with mutually agreed-upon diplomatic arrangements.  By definition, however, the United States, Iran and the other five signatories would have international obligations to comply with a legally binding agreement, and no such legal obligations to comply with a non-binding agreement.

So, will the Iran deal, if finalized, be such a nonbinding agreement among the seven parties—with incentives for compliance but no obligations enforceable under international law?

It appears that it will be, at least if the U.S’s expectations are borne out.  In yesterday’s press briefing, State Department spokesperson Jen Psaki repeatedly referred to the parties negotiating “political commitments,” and described the prospective deal as “a nonbinding international arrangement, to be signed (if it is signed) by the United States, the United Kingdom, France, China, Russia, Germany, and Iran,” in which Iran will make “verifiable and enforceable commitments to adhere to . . . limits.”

“Historically, under many administrations,” Psaki said, “the United States has pursued important international security initiatives through nonbinding arrangements where that has been in our national interest.  In the arms control and nonproliferation area alone, some representative examples include the U.S.-Russia deal to remove chemical weapons from Syria, the Proliferation Security Initiative, the Nuclear Supplier Group Guidelines, [and] the Missile Technology Control Regime. There’s a lot of precedent for this being political commitments made by all sides.”

Likewise, back in January, White House Press Secretary Josh Earnest said that “a congressional vote on a nonbinding instrument is not required by law and could set an unhelpful precedent for other negotiations that result in other nonbinding instruments.”  [See also Tyler Cullis’s letter to Just Security last July.]

There may be tricky questions about the sources and proper scope of the President’s power to make sole Executive agreements that bind the United States under international law.  But if, in fact, the “P5+1” and Iran conclude a nonbinding “political” agreement, there is little doubt about the President’s constitutional authority to make the deal on his own.

A final caveat:  The line between legal and non-legal agreements is not always clear, and one can imagine that there remains some play in the joints on this issue in the current negotiations (which might explain Foreign Minister Zarif’s references to “international obligations”).  Also, an entirely different set of arguments and concerns might come into play if the parties were to sign a non-binding agreement that becomes the basis for a legally binding Security Council Resolution.