Will Afghanistan become united and systematic under the Taliban. I doubt it.

After the Vietnam war the US supported the Khmer Rouge in an attempt to destabilise Vietnam.

To be defeated and the the victors to establish a stable administration seems not to to be a favourite outcome for the US.

Expect covert funding to be funnelled to the Taliban's opponents and civil war to resume.

If the Taliban were to establish a stable administration that would be awful too.

There does not seem to be any good outcome possible.