I think we should definitely, on the quiet, explain to all the governments of the region, and tell them to get the message to the terrorists, that any more strikes on the US, and we will nuke Mecca. Some might say that this will mean war with 900 million Muslims. I think it might be a heavy psychological blow for them. If their moon god was real, would he really let us blow up their meteor? I don't think so.
SO....their choice is, go back to their pathetic existence, and watch modernity bring the stupidity of their raghead culture and religion to light, slowly extinguishing it from the planet, or have it extinguished for them by force if they try to impose it on the civilized world. If they are smart, they will choose the former, where they can continue to enjoy their heritage and hope for better days, rather than the latter, which will ensure a massive loss of life and the death of their culture.
So what do we do if the apocolypse hit the US? Really good question. We could threaten Iran and Pakistan to catch bin Laden, but our military is already spread too thin. Killing innocent Arabs is no better than killing innocent Americans. The only credible thing is probably begin nuking the areas where bin Laden and company have been known to hide, like the southeastern mountains along the Afganistan-Pakistan border.
Let's hope these threats are false bravdo, and Specials Ops somehow capture or kill the head of the Al Queda dragon.