Key point: A proxy war that we are still paying for.
In 1977, General Muhammad Zia-ul-Haq overthrew Pakistan’s civilian president in a coup. He proceeded to institute hardline Islamist laws throughout Pakistan, and began rebuilding Pakistani military power after its humiliating defeat in a 1971 war with India.
Following the Soviet invasion of Afghanistan in 1979, Washington found that Zia’s policies dovetailed conveniently with getting Pakistani assistance in supporting Mujahideen insurgents fighting Communist forces. Thus, Pakistani and U.S. agents collaborated in organizing and arming militants proliferating in Afghan refugee camps in Pakistan.
In retaliation, Soviet and Democratic Republic of Afghanistan Air Force (DRAAF) jet bombers began crossing into Pakistani airspace to blast those refugee camps. The Pakistani military deployed J-6 fighters (Chinese-built MiG-19 clones) capable of Mach 1 speed and two radars to defend the border, but these proved too slow and the patrol and radar coverage too spotty, so none of the raids were intercepted.
Thus in 1981, Zia persuaded the Reagan administration to authorize sale of forty F-16As and two-seat F-16Bs, which would be received between 1983-1986. The then cutting-edge fourth-generation fighter was affordable, extremely maneuverable due to its aerodynamically unstable design (compensated for with fly-by-wire controls), and could still attain high speeds and carry heavy payloads.