Bin Laden's wealth and connections assisted his interest in supporting the mujahideen, Muslim guerrillas fighting the Soviet Union in Afghanistan following the Soviet invasion of Afghanistan in 1979. His old teacher from the university in Jeddah, Abdullah Azzam, had relocated to Peshawar, a major border city in the North-West Frontier Province of Pakistan. From there, Azzam was able to organize resistance directly on the Afghan frontier. Peshawar is only east of the Khyber Pass, through the Safed Koh mountains, connected to the southeastern edge of the Hindu Kush range. This route became the major avenue of inserting foreign fighters and material support into eastern Afghanistan for the resistance against the Soviets.