The Joint Plan of Action (JPA) negotiated between Iran and the United States and its partners in the P5+1 accomplishes a great deal in the short run, but its success remains uncertain, pending the negotiation of long-term arrangements. The JPA's interim steps, which began on January 20, 2014, are technically sound and lengthen Iran's breakout time to make enough weapons-grade uranium for nuclear weapons, establish transparency over many previously opaque Iranian nuclear activities, and freeze and even temporarily reverse key portions of the nuclear program. The JPA, however, leaves many key issues unsettled regarding a long-term, comprehensive solution.

The test of the JPA lies in negotiating these long-term arrangements, a process President Obama gives a 50-50 chance of succeeding. A final agreement must create long-term, meaningful limits on Iran's nuclear program combined with adequate verification sufficient to ensure that any attempt by Iran to build nuclear weapons would be detected in a timely manner and provide adequate time for an international response.
 
To improve the chances of success, the United States needs to clearly state its goals and be willing to walk away from a bad deal, particularly also if the administration judges that a deal is unlikely in the face of Iranian delays and unreasonable demands. If a comprehensive solution cannot be negotiated by the end of the interim period, the United States should increase economic sanctions on Iran and move to further its political isolation, while avoiding military strikes. Given the relatively low chances of success, the United States would be prudent to plan for such a possibility today. Doing so would also reinforce a critical message to the international business community and other governments that this crisis is not over and sanctions have a 50-50 chance of being reapplied and strengthened.