Would new Iran sanctions help U.S. negotiators? Probably not.

(Stan Honda/AFP/Getty Images)

Even while the U.S. prepares for new talks with Iran, the Senate is discussing imposing new sanctions. Despite intensive lobbying from the White House, some prominent senators are suggesting that new sanctions would help U.S. negotiators, not hurt them.

“From my perspective, it strengthens the administration’s hand” and positions the United States “for the possibility that [a permanent] agreement cannot ultimately be struck,” [Senate Foreign Relations Committee Chairman Robert] Menendez said of a new sanctions bill. “It would make clear to the Iranians if they don’t strike a deal, this is what’s coming. “I find it interesting that the Iranians can play good cop, bad cop with ‘hard-liners’ in their country,” he added, while “we can’t.”

Robert Putnam’s classic article on two-level diplomacy provides a framework for thinking about Menendez’s argument (this article by Andrew Moravcsik is also very helpful, and skips the math). Putnam argues that negotiators have to deal simultaneously with international negotiators (whom they bargain with to get a deal) and domestic audiences (which may or may not be prepared to accept a deal). A deal is possible where the ‘win sets’ of the international negotiators intersect (that is, where there is some crossover between the set of possible agreements which is acceptable to one side, and the set of possible agreements that is acceptable to the other). However, negotiators may also have incentives to force concessions from the other side by making their win sets look narrower than they are (i.e. pretending that they will not accept agreements that they are in fact prepared to accept). They may also win concessions if they “tie their hands” by making ratification dependent on the approval of hardliners.

Some version of this lies behind Menendez’s argument – if this theory is right, then political divisions back home can make a negotiator stronger, not weaker. They allow the negotiator to argue that her hands are tied, so that she can avoid concessions that she would otherwise have to make. Menendez is arguing that the Iranians are using their own domestic divisions to strengthen their hands in negotiations. Because any agreement will have to satisfy Iranian hardliners, the Iranian negotiators are able to play tough, and extract benefits from the U.S.

Menendez seems to think that the US needs its own hardliners too, to narrow the U.S. win set, so that it doesn’t make concessions that it shouldn’t be making. New sanctions legislation would make it clear to Iran both that Senate ‘ratification’ (i.e. passing legislation to roll back sanctions) is going to be very hard and that failure to reach an acceptable deal will hurt Iran.

The problems with this line of reasoning are twofold. First, there isn’t any very good evidence that it works on its own terms. In the words of Peter Evans:

The strategy of ‘tying hands’ – deliberately shrinking the win-set in pursuit of an agreement closer to the [negotiator’s] preferred outcome – is infrequently attempted and usually not effective. The ‘tying hands’ strategy, suggested by Thomas Schelling’s work, is logically plausible but lacks efficacy in practice. Perhaps because they are aware of its limited efficacy, statesmen prefer not to have their ‘hands tied’ by constituents, even when they share the constituents’ preferences

Second, it can be very risky. It can easily go too far, by shrinking the perceived win set down so much that there is no longer any possible agreement. Any final deal will have to get sign-off from the House and Senate, which will both have to roll back the sanctions legislation that is already in place. New sanctions may lead the Iranians to conclude that there isn’t any possible deal that would pass the House and Senate and also be acceptable to Iran.

Plausibly, shrinking the win set too much will be riskier when the actors doing the shrinking don’t have a detailed grasp of the nuances of the negotiations. The risk will obviously be even higher if these actors have to compromise with others who sincerely want the negotiations to fail. Both conditions seem to apply to the Senate’s threats.

It’s certainly possible that Menendez is right – that hardline posturing by the Senate will influence negotiations to the benefit of the U.S. without any risk. However, it’s probably not the way you should be betting.