The Cooperation Council for the Arab States of the Gulf (Arabic: مجلس التعاون لدول الخليج العربي), originally (and still colloquially) known as the Gulf Cooperation Council (GCC; Arabic: مجلس التعاون الخليجي), is a regional, intergovernmental political and economic union that consists of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. The council's main headquarters are located in the city of Riyadh in Saudi Arabia. The Charter of the GCC was signed on 25 May 1981, formally establishing the institution.All current member states are monarchies, including three constitutional monarchies (Qatar, Kuwait, and Bahrain), two absolute monarchies (Saudi Arabia and Oman), and one federal monarchy (the United Arab Emirates, which is composed of seven member states, each of which is an absolute monarchy with its own emir). There have been discussions regarding the future membership of Jordan, Morocco, and Yemen (Yemen being the only country of the Arabian Peninsula not yet a member of the GCC).During the Arab Spring in 2011, Saudi Arabia raised a proposal to transform the GCC into a "Gulf Union" with tighter economic, political and military coordination, regarded as a move to counterbalance the Iranian influence in the region. Objections were raised against the proposal by other countries. In 2014, Bahrain prime minister Khalifa bin Salman Al Khalifa said that current events in the region highlighted the importance of the proposal. The Peninsula Shield Force is the military arm of the GCC, formed in 1984.