Did the Reagan administration indirectly create Al-Qaeda?

In a way. The politics of it are pretty complex. Blaming reagan for it would be too simple. They helped them become an organized fighting force and armed them (along with training). The motivation, though, was all their own. Part of the reason that Al Qaeda was created was extremist muslims opposing our relatively "loose" culture. Another part could be the perceived abandonment of them after America pulled out of Afghanistan (before 9/11). After the soviet government fell, the afghan rebels turned to fighting each other for power and territory. This infighting made afghanistan's a practical warzone, almost civil war. America was, to them, a place to cast blame and therefore a way to recruit new soldiers who had been devastated by the fighting (and this was many)