I agree with you in terms of the timing. AQ has been trying to isolate the US in Iraq. They were successful in getting the Spanish to pull out and now they are working on the Brits, especially now that Blair is gone. We will be the last big target after they have isolated us. And they will wait until the political timing is right.
Why not the United States? Well, gee, how about the simple reason that the Muzzies know that the negatives would far out-weight the positives of such an attack on the U.S. It would weaken their allies in the U.S. (that would be the Democrat Party), and would piss off the American people (who already seem to be forgetting about 9/11).
My thought:
To attack here would go against their goal of convincing the American public that the Dems are right, and that the threat of Islamo-fascism is overblown. Once we pull out, expect continued (indeed, increased) attacks on Americans abroad, especially in areas where the majority of the population is Islamic. They want to chase us from the world stage first, and separate us from our allies. They won’t be coming for us until they have taken over Europe. We should be allying with China and non-Muslim India.
Having given this a lot of thought, the only way I see this conflict ending with Western values surviving is if the people of Islam reject the text of their religion which calls for the conversion of nonbelievers by force or, barring that the outlawing of Islam.
The Muslims also know that the next time there is another hit, unlike 9/11, they know that THERE WILL BE an outright angry backlash, complete with violent revenge attacks to what the Muslims hold dear.