Rejection of the deal would damage U.S. leadership in Middle East at a critical time
First, scuttling the negotiations would diminish U.S. credibility and reduce cooperation from the coalition that has helped get us the interim deal. The United States, Britain, France, Germany, Russia and China each have been integral to this process. Unilaterally changing our demands at this point, before all the parties have had a chance to conclude and internally vet an agreement, would prove a losing strategy.
U.S. credibility in the volatile Persian Gulf region and the Middle East already is strained. By proceeding now and ignoring the rest of the parties to this potential agreement, we make it easier for the most unwilling of them to walk away from the negotiations with the excuse of U.S. “bad faith.” Perhaps more importantly, we risk further alienating some of our most valued allies when we need them most. That will turn the tide against our own interests, an especially perilous proposition as we rally the fight against ISIS.
If the U.S. congress rejects the nuclear deal with Iran, it will have multiple negative reprecussions for U.S. interests and security. The most likely impact of U.S. rejection of the deal will be a gradual collapse of the sanctions regime as our partners have no interest in reopening negotiations with Iran and are already starting to renew trade relations. Additionally, rejection of the deal will damage U.S. credibility as a global leader and its diplomatic capital for many years as the U.S. was critical in forming the consensus for the deal in the first place.