Total armed forces numbered approximately 50,000–55,000 in 2002. The army numbered 40,000 armed with over 300 main battle tanks. The air force numbered between 10,000 and 15,000 and operated 135 combat aircraft and 452 attack helicopters. In addition, there were about 18,000–20,000 internal security forces and a national guard of 1,000 organized into a single brigade. Government troops faced opposition from an estimated 2,000-member Islamic Movement of Uzbekistan. The defense budget for 1997 was $200 million or 1.4% of GDP.