This isn't true. Up until the fall of the Soviet Union, there was an Afghan state that was able to motivate enough of the population to believe in it and fight

This isn't true. Up until the fall of the Soviet Union, there was an Afghan state that was able to motivate enough of the population to believe in it and fight for it in order to largely defeat the Mujahideen. Were it not for external support for the Mujahideen, it is almost certain that an Afghan state would have succeeded in achieving some form of monopoly on violence. The idea that nation-states were something alien to Afghanistan that we had to force on them just isn't true.