well, the jihadists were rebelling even before the russians came in because of the secular modernisation being imposed by the regime in afghanistan. got them real mad. apparently every time a govt goes left enough its time to dig up the bones of millions dead to justify whatever we do to it.
The number - 100,000,000 - is astounding. It can't be underestimated. This was a force that had our names on it, and without resistance, heavy resistance, it would have dominated the planet.
The people of Afghanistan are a piteous people for all they've suffered. But I think we can blame the backwardness of the Islamic culture that put them in a position where they couldn't fight for their own freedom in the colonial days, and in the Cold War.
But no matter where the Soviets went with their Marxist Imperialism, they had to be stopped at any cost.