Orwell said:It worked with the Soviets and it worked with the US (you were as afraid of them as they were of you).
But it probably won't work with Muslim extremists. They want to radicalise the conflict, I think that one of their main objectives is to provoke the west into butchering innocent Muslims in response to a terrorist attack, in the hopes of driving more people in their true target audience (the Muslim world) to their extremist ideology. It is quite probable that, from their point of view and in spite of their alleged religious convictions, the US bombing Mecca would be the best possible scenario...
This is a definite possibility. The whole point of the threat is to make it less likely to get to the point where you actually need to do anything.
As you say, the problem comes when the enemy WANTS you to do something. They'll provoke you until you bite.
One problem with not biting is of course that it will just make the next provocation more provocative.
I do not know how the nut-cases think, but for the recruiting, it may be difficult to recruit more people to support a cause that will lead to the destruction of what they hold dear.
With a little (more than usual) luck, the average muslim (whoever that is) may decide that it is more in the interest of Islam to get rid of the nut-cases than to join them. If enough muslims get that idea, recruiting will be much more difficult.
How much damage can the nut-cases do before the destruction of Islam becomes a (the?) major vote-collector in the West? Are "muslims" aware of this possibility? Do they know just WHY there is no really heavy hands from the West? (And I don't think of Afghanistan and Iraq as "heavy hand") Do they really want to push the West into real war? Not just the play-stuff done so far...
Europeans do not have much experience with this "peace over generations"-stuff. Easily provoked into war, a growing uneasiness about a rapidly growing and demanding muslim population... If setting off WWIII is a goal of islamists, Europe may be a better target than USA. And the result may be very, very bad.
Mosquito - Rambling way outside what I know much about (=business as usual)