The nuclear deal, by facilitating more transparency and on-site inspections of Iran's nuclear facilities will also improve U.S. intelligence on known facilities, improving the military's ability to target these at a later point.
The success of U.S. sanctions against Iran is due in part to the multilateral cooperation achieved through the P5+1 negotiations with Iran, but also because of overall U.S. dominance of the global financial system. The U.S. has developed a number of systems through its financial institutions that have allowed it to track the flow of money being used to support terrorist groups or countries under sanction such as Iran. If the U.S.
The Rouhani administration was swept into power by voter frustration with the lagging Iranian economy, devastated by economic sanctions. The Iranian public is overwhelmingly in favor of the nuclear deal because it anticipates that any sanctions relief will be spent at home on domestic priorities and will hold Iranian politicians to that demand.
The U.S. is committed to reducing the destabilizing impact of Iran's foreign policy in the region even after the nuclear deal. Existing sanctions and financial instruments against Iran's support for terrorist groups will remain in effect under the nuclear deal and the U.S. is reaching out to its GCC partners to further cooperate to contain Iran.
Iran has a long history of supporting terrorist proxies and promoting an aggressive foreign policy that has caused instability in the region. However, we should be careful not to overstate the impact or threat from their regional ambitions as they have had limited success in spreading their revolutionary ideology. Additionally, recent instability in Iran's traditional spheres of influence (ex. ISIS and Syria), is forcing them to refocus their efforts and reduce funding for other activities.
U.S. allies in the gulf region are right to be concerned about an empowered and unfettered Iran after the nuclear deal. Additionally, there are concerns that the growing U.S.-Iranian rapproachment will further destabilize the Middle East.