I have been amazed by the hysterical talk of 'carpet bombing', etc. in the media. Clearly that would never work. However there is negligible up to date intelligence on Afghanistan, therefore it is clear that the SAS would be used for reconnaissance.
This is what they are best at and would provide the essential information to carry out surgical strikes. Without such reconnaissance nothing can be done and it would take several weeks to gather the required information.
The civilised world is in no rush to get at the terrorists - except for the fact that they could commit some other awful act. They have now had three weeks to gather information so it will not be long now before action is taken.