From the Summary: "The State of Qatar, a small Arab Gulf monarchy which has about 300,000 citizens in a total population of about 2.4 million, has employed its ample financial resources to exert regional influence, often independent of the other members of the Gulf Cooperation Council (GCC: Saudi Arabia, Kuwait, Qatar, United Arab Emirates (UAE), Bahrain, and Oman) alliance. Qatar has fostered a close defense and security alliance with the United States and has maintained ties to a wide range of actors who are often at odds with each other, including Sunni Islamists, Iran and Iran-backed groups, and Israeli officials. [...] Qatar's leaders work with the United States to secure the Persian Gulf, as do the other GCC leaders. The United States and Qatar have had a formal Defense Cooperation Agreement (DCA) that reportedly 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 more than 8,000 U.S. forces and the regional headquarters for U.S. Central Command (CENTCOM) at various military facilities, including the large Al Udeid Air Base. U.S. forces deployed at these facilities participate in operations throughout the region. Qatar is a significant buyer of U.S.-made weaponry, including combat aircraft. In January 2018, Qatar and the United States inaugurated a 'Strategic Dialogue' that has included discussion of efforts to improve accommodations for U.S. personnel deployed to Al Udeid Air Base, which has been used extensively in the U.S. operation to evacuate U.S. personnel and Afghan allies from Afghanistan in August 2021."
CRS Report for Congress, R44533
Congressional Research Service: https://crsreports.congress.gov/