Not entirely the fault of communists. Islamist groups were also agitating in Afghanistan and given Pakistan's trajectory (under Bhutto) would likely have set off a civil war as well.

A narrow rent-seeking elite in a desperately poor country isn't a model for stability which pre-communist take over Afghanistan was.

Just as you can't hand wave at everything with the "it was the US", you shouldn't hand wave at everything as it was the communists fault.