A large portion of Congress is poised to vote for a bill that would intensify sanctions against Iran in the middle of the talks currently underway. 

This is a terrible idea.  Instead, Congress should follow the lead of the White House but have the toughest sanctions ever prepared ready for vote should the current talks fail. 

Tehran has already announced that it will leave the talks if Congress passes the bill (and an override on a veto is possible).  The problem is that the US, not Iran, would be blamed for the talks’ breakdown because of the commitment in the P5 +1 interim agreement to refrain from initiating new sanctions while the talks continue. The U.S. would then violate the agreement in a blatant manner if Congress passes the act. 

The problem with the discussion over the proposed bill so far is that there has been little consideration of what the actual alternative conditions are. 

If there is no bill:  The talks will continue over an extended period, perhaps even longer than the six months that are now scheduled if both sides agree.  Meanwhile, there is some minimum relief from Iranian sanctions, but the Iranians cannot advance their nuclear program and are being rigorously inspected, far more intensely than before the interim agreement.  So the nuclear program will not be dismantled, but it is now frozen in its tracks. This is no small achievement.  

The talks will either succeed or fail.  If the former, the Iranians will have to reduce their nuclear program, probably accept limited enrichment, and a new inspection regime will be emplaced.  Such issues as human rights and terrorism will not be addressed, but certainly the U.S. and its allies will be in a far better position to deal with these issues than they would be in if the talks collapse. 

If the talks fail because no agreement can be reached, then the parties will return to their previous positions: Iran will presumably resume its march to a nuclear force; the U.S. will intensify sanctions to a new level and renew consideration of the military option. 

If the bill passes:  The key question will be who will be blamed for the talks breaking down.  The supporters of the bill confidently predict that Iran is bluffing on its threat to leave the talks. 

The proponents fail to explain their demand that the sanctions can only be lifted when Iran agrees to dismantle its “illicit nuclear infrastructure.” That would be fabulous, but it was also the position of the Bush administration when the Iranians turned to dramatically expanding their nuclear preparations.   Because the bill is much harsher than the interim accord, and requires Presidential actions that reinforce the policy of Congress, it is really inconceivable that the Iranians would remain in the talks. 

If the interim agreement appears to be upended by actions of the U.S. Congress,  it will be incomparably more difficult, to gain international support for sanctions and military action.  In that sense, the Legislative branch voting sanctions now could actually create the worst of both worlds: Iran will walk away from the talks as the offended party, and sanctions will be diminished as the Iranians develop an excuse to complete their nuclear ambitions. Congress should not give Teheran an opportunity for such a victory. 

By contrast, if talks break down due to Iranian intransigence, Congress would undoubtedly pass the bill immediately.  The Department of Treasury should be charged now with preparing for the bill’s passage on a contingency basis.  There would be intense American and international support for new sanctions, and a military option will then necessarily be on the table. Iran should be made to understand these contingencies clearly. 

Some argue that Israeli security will be aided by this bill.  It is difficult to see how:  If the sanctions regime loses support internationally and the military option becomes more difficult to justify, that’s not a victory for Jerusalem. 

Congress has successfully bolstered America’s negotiating position by demonstrating what will happen if Iran does not come to an agreement, but in diplomacy parties must realize when it is time to step back, even temporarily.  The bill is ready, but it should not be approved pending the progress of the talks.  Meanwhile, the United States can only have one set of negotiators at a time.  Imagine if Congress had prevented Richard Nixon from traveling to China.  How different and more deadly a future would have been in store. 

The legislative branch has made its point and demonstrated that Washington will not be asleep if the talks fail.  It is now time to let the executive branch try to reach an agreement.  That approach would be America at its best.  

Spiegel is professor of Political Science and director of the Center for Middle East Development, UCLA.