the Turkestan Military District of the Soviet Army. The Uzbek Armed Forces' equipment is standard, mostly consisting those of post-Soviet inheritance and newly crafted Russian and some American equipment. The government has accepted the arms control obligations of the former Soviet Union, acceded to the Nuclear Non-Proliferation Treaty (as a non-nuclear state), and supported an active program by the U.S. Defense Threat Reduction Agency (DTRA) in western Uzbekistan (Nukus and Vozrozhdeniye Island). The Government of Uzbekistan spends about 3.7% of GDP on the military but has received a growing infusion of Foreign Military Financing (FMF) and other security assistance funds since 1998. Following 11 September 2001 terrorist attacks in the U.S., Uzbekistan approved the U.S. Central Command's request for access to an air base, the Karshi-Khanabad airfield, in southern Uzbekistan. However, Uzbekistan demanded that the U.S. withdraw from the airbases after the Andijan massacre and the U.S. reaction to this massacre. The last US troops left Uzbekistan in November 2005. In 2020, it was revealed that the former US base was contaminated with radioactive materials which may have resulted in unusually high cancer rates in US personnel stationed there. Yet the government of Uzbekistan has denied this statement claiming that there has never been such a case. On 23 June 2006, Uzbekistan became a full participant in the Collective Security Treaty Organization (CSTO), but informed the CSTO to suspend its membership in June 2012. Culture Uzbekistan has a wide mix of ethnic groups and cultures, with the Uzbek being the majority group. In 1995 about 71% of Uzbekistan's population was Uzbek. The chief minority groups were Russians (8%), Tajiks (3–4.7%), Kazakhs (4%), Tatars (2.5%) and Karakalpaks (2%). It is said, however, that non-Uzbeks decline as Russians and other minority groups slowly leave and Uzbeks return from other parts of the former Soviet Union. When Uzbekistan gained independence in 1991, there was concern that Muslim fundamentalism would spread across the region. The expectation was that a country long denied freedom of religious practice would undergo a very rapid increase in the expression of its dominant faith. According to a 2009 Pew Research Center report, Uzbekistan's population is 96.3% Muslim, around 54% identifies as non-denominational Muslim, 18% as Sunni and 1% as Shia. And around 11% say they belong to a Sufi order. Music Central Asian classical music is called Shashmaqam, which arose in Bukhara in the late 16th century when that