The Taleban wasn't a 'disgusting' regime to the Americans when it suited them to support it in fighting the Russians. So, when does a useful, onside regime become disgusting? When it outlives its use or decides that just because it aligned itself with its enemy's enemy does not, in fact, make it its enemy's friend. The Taleban wanted the godless Russians out, out, out - but they didn't want a load of Western decadence either.
There are no moral absolutes - we may start out with what we think are 'moral' values (well, moral to us, if not to everyone else), which is what the Taleban did. I have no love for them at all, but they were very handy to the West at one stage, which found it expedient to put aside its 'moral' revulsions.
The Wahhabis helped to put the House of Saud back in power in the 1920s and while you call them 'vile', clivex, they actually helped a very 'moral' sheikh to overcome a despotic one (Rashid). They are the Sunnis' Sunni, the eminence grise in the background to the royal family and the antipathy of Shi'ite belief. The running gun battles fought regularly in the kingdom, and singularly unreported in the partisan Western media, are not with 'vile' Wahhabis, but with dissident Shi'ites and alleged Al-Queda gangs, either of which would be delighted to see the end of the Sauds' reign and instigate their own.
So, let's see: the Wahhabis are vile, and the Taleban are disgusting. Two fundamentalist beliefs you presumably think should be repressed. Curious that the first assisted the Sauds to establish 'Saudi' Arabia and thus bring in the Americans, drill for oil, and keep the West in petrol (and if you drive a car, then your car in petrol, too); in the second case, a very useful and dedicated ally in driving the Commies out of a foothold in Afghanistan and an eventual drive towards the oilfields of Iran, Kuwait, and goodness knows where.
