Law360, New York ( April 14, 2015, 10:21 AM EDT) -- In what may represent a sea change in U.S.-Iran relations, on April 2, 2015, Iran and the United States, along with the United Kingdom, France, Russia, China and Germany, announced the key parameters of a Joint Comprehensive Plan of Action (JCPOA) to limit Iran's nuclear program in exchange for lifting U.S. and international sanctions.[1] However, many challenges remain, including whether these parameters — which leave many details still to be negotiated by the June 30 deadline for completion of the JCPOA — will be successfully converted into a deal. Even if a deal is reached, it will have to overcome political opposition from members of the U.S. Congress who have introduced legislation that would mandate congressional review and approval of any agreement with Iran, and from close U.S. allies, such as Israel and Saudi Arabia....