I'm not aware of any evidence that the Afghan war has had any adverse effect on the ability of the Al Qaida network to recruit and train recruits, and carry out attacks. And there is very strong reason to believe that it may have had the opposite effect.

The crucial weapon involved is not technological, it is human - once you have human beings who are willing to die in the course of carrying out the instructions, the rest is just detail. Pocket knives, fertiliser, backpacks - nothing high tech needed, no complicated training.

That is why the essential thing is to avoid providing that essential key weapon, the person who is motivated to give his or her life. Everything that has been done so far could have been designed to make it easier to recruit such people, by motivating increased numbers to feel that way.