"The UAE has been a significant U.S. partner in Gulf security for more than two decades, and the alliance has deepened further in the course of U.S.-led efforts to pressure Iran to agree to strict limits on its nuclear program and to try to defeat the Islamic State organization. Under a 1994 U.S.-UAE defense cooperation agreement (DCA), about 5,000 U.S. military personnel are stationed at UAE military facilities, particularly the large Al Dhafra air base. The UAE was the first Gulf state to order the most sophisticated missile defense system sold by the United States (the THAAD), demonstrating support for U.S. efforts to assemble a coordinated regional missile defense network against Iran. The UAE has a long-standing territorial dispute with Iran and has implemented economic sanctions against it, even though doing so has adversely affected some of the UAE's large and politically influential trading community. Suggesting continued wariness of Iranian ambitions in the Gulf, the UAE has sought U.S. assurances that the United States will maintain its commitment to Gulf security. Regionally, the UAE has become increasingly assertive against extremist Islamic organizations, to the point of undertaking even some unilateral military action in post-Qadhafi Libya. The UAE has joined U.S.-led airstrikes against the Islamic State in Syria; financially assisted the military-led government of Egypt that ousted the elected Islamist president in 2013; supported moderate Islamist rebel groups in Syria; and worked against other Muslim Brotherhood-related organizations in the region such as Hamas."
CRS Report for Congress, RS21852
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html