The state of Qatar, a member of the Gulf Cooperation Council (GCC: Saudi Arabia, Kuwait, Qatar, United Arab Emirates, Bahrain, and Oman), has employed its ample financial resources to try to "punch above its weight" on regional and international affairs. Qatar has intervened, directly and indirectly, in several regional conflicts, including in Syria and Libya. Qatar also has sought to establish itself as an indispensable interlocutor on some issues, such as those involving the Palestinian Islamist organization Hamas, the Taliban insurgent group in Afghanistan, some Al Qaeda-linked Syrian rebel groups, Lebanon, and Sudan. On Iran, Qatar has generally supported efforts to limit Iran's regional influence while maintaining dialogue with Iran's senior officials. However, Qatar's policies - particularly its support for regional Muslim Brotherhood organizations as a positive example of "political Islam" - continue to plague relations between Qatar and some other GCC members. Saudi Arabia and the UAE assert that the Brotherhood is a threat to regional and domestic security and have taken generally opposed engaging Iran diplomatically. The differences erupted into a crisis on June 5, 2017 when Saudi Arabia, the UAE, and Bahrain, joined by Egypt and a few other governments, severed relations with Qatar and imposed limits on the entry and transit of Qatari nationals and vessels in their territories, waters, and airspace. The United States and several regional governments called for dialogue to resolve the rift and the United States is seeking to mediate the dispute, which threatens to fracture U.S. efforts to mobilize a regional coalition against Iran and against terrorist groups. The United States and Qatar have had a formal Defense Cooperation Agreement (DCA) since 1992, which addresses a U.S. troop presence in Qatar, consideration of U.S. arms sales to Qatar, U.S. training, and other defense cooperation. Under the DCA, Qatar hosts nearly 10,000 U.S. forces at its military facilities, including at Al Udeid Air Base, and Qatar also hosts the regional headquarters for U.S. Central Command (CENTCOM). U.S. forces in Qatar participate in operations all over the region, including Operation Inherent Resolve (OIR) against the Islamic State organization in Iraq and Syria, and in Afghanistan. The Qatari government is helping the United States combat regional Islamist terrorist organizations. However, radical Islamist organizations profess ideologies that are attractive to some Qatari citizens, and there have been repeated accusations by international observers that wealthy Qataris have contributed funds and services to these groups. The voluntary relinquishing of power in 2013 by Qatar's former Amir (ruler), Shaykh Hamad bin Khalifa Al Thani, departed sharply from GCC patterns of governance in which leaders generally remain in power for life. Even though Qatar's former Amir stepped down voluntarily, U.S. and international reports criticize Qatar for numerous human rights problems. Most of them, such as suppression of critics using social media and deprivation of labor rights, are common to the other GCC states. A recent Gulf-wide trend also apparent in Qatar has been a crackdown on dissent against the ruling establishment on social media networks. Qatar is also the only one of the smaller GCC states that has not yet formed a legislative body that is at least partly elected, even though such elections have long been promised. Qatar is wrestling with the downturn in global hydrocarbons prices since 2014, as are the other GCC states. Qatar is positioned to weather the downturn because of its small population and substantial financial reserves. Qatar shares with virtually all the other GCC states a lack of economic diversification and reliance on revenues from sales of hydrocarbon products.