Since reunification in 1975, Vietnam has emerged as one of the world's leading military powers. As of 2002, the People's Army of Vietnam was estimated at 484,000. Of that figure, the regular army had about 412,000 personnel, the air force 30,000, and the navy 42,000. Reserves numbered between 3–4 million. Armaments included about 1,200 main battle tanks, 629 light tanks, two submarines, six frigates, 189 combat aircraft, and 26 armed helicopters. There is a border defense corps of 40,000 personnel. Also, local forces may number between 4–5 million in a rural unit people's militia. Military expenditures were $650 million in 1998 or 2.5% of GDP.