… it literally isn’t. The Taliban wasn’t a ‘splinter group’ of the Mujahedeen government, it was a largely Pakistani-funded and supported initiative whose even most embryonic form post-dates the entire Soviet-Afghan War in creating a paramilitary with the express purpose of overthrowing the previous Mujahedeen government (a goal in which it succeeded).
How is it fallout from that?
Because it’s formed from a splinter group of the previously installed government?
… it literally isn’t. The Taliban wasn’t a ‘splinter group’ of the Mujahedeen government, it was a largely Pakistani-funded and supported initiative whose even most embryonic form post-dates the entire Soviet-Afghan War in creating a paramilitary with the express purpose of overthrowing the previous Mujahedeen government (a goal in which it succeeded).