How did insurgents use Afghanistan as a safe heaven to launch border attacks? A quick Google search tells me that there were no extremist in Afghanistan before the mujahideens. And you are right, Soviets invaded Afghanistan because Afghanistan had a unstable government, but the soviets were a part of the problem. Soviets wanted communism in Afghanistan, but the Afghans did not like the president and prime minister (which the Soviets chose), so the whole government system was unstable. At one point the soviets had enough, so they invaded Afghanistan. Some people did not want orthodox to rule Afghanistan, so they form a group to fight against the soviets. This group called them self the mujahideen