The TB are a homegrown Afghani entity - AQ is a foreign agent who inserted themsleves into and were allowed [for whatever reason(s)] to thrive relatively unmolestedly in territory
'presumably' under TB control.
The unilateral actions of AQ brought the wrath of the free world down upon the TB as a collateral effect of our efforts to defang AQ...and it has not been a pleasant experience for them or their supporters.
After the last decade and
IF the TB returned to power in Afghanistan, I suspect they would have little desire or internal national support to even consider inviting the return of AQ and a renewal of the problems they brought to the TB.
I agree with BV - a return of the TB = a return of AQ
is an 'assumption' which IMO doesn't necessarily ring true.
Richard
