With the active encouragement of the CIA and Pakistan's ISI [Inter Services Intelligence], who wanted to turn the Afghan jihad into a global war waged by all Muslim states against the Soviet Union, some 35,000 Muslim radicals from 40 Islamic countries joined Afghanistan's fight between 1982 and 1992. Tens of thousands more came to study in Pakistani madrasahs. Eventually more than 100,000 foreign Muslim radicals were directly influenced by the Afghan jihad.3

The Islamic "jihad" was supported by the United States and Saudi Arabia with a significant part of the funding generated from the Golden Crescent drug trade:

In March 1985, President Reagan signed National Security Decision Directive 166,...[which] authorize[d] stepped-up covert military aid to the mujahideen, and it made clear that the secret Afghan war had a new goal: to defeat Soviet troops in Afghanistan through covert action and encourage a Soviet withdrawal. The new covert U.S. assistance began with a dramatic increase in arms supplies -- a steady rise to 65,000 tons annually by 1987, ... as well as a "ceaseless stream" of CIA and Pentagon specialists who traveled to the secret headquarters of Pakistan's ISI on the main road near Rawalpindi, Pakistan. There the CIA specialists met with Pakistani intelligence officers to help plan operations for the Afghan rebels.4

The Central Intelligence Agency (CIA) using Pakistan's military Inter-Services Intelligence (ISI) played a key role in training the Mujahideen. In turn, the CIA sponsored guerrilla training was integrated with the teachings of Islam:

Predominant themes were that Islam was a complete socio-political ideology, that holy Islam was being violated by the atheistic Soviet troops, and that the Islamic people of Afghanistan should reassert their independence by overthrowing the leftist Afghan regime propped up by Moscow.5

he mujahideen predecessors of the UIF forces previously showed themselves unable to rule effectively, turning on each other after they took control in Kabul in 1992 from the Soviet-backed regime. The UIF's predecessors were responsible for brutal excesses during the factional civil strife that raged after the collapse of the Communist government. This bloody feuding between forces loyal to President Burhanuddin Rabbani and rival factions ultimately cleared the way for the Taliban conquest in 1996.