Bin Laden's truce offer is for Iraq and Afghanistan only, not for the U.S.
Which is to say, he'd rather fight the war here in the U.S. (e.g. 9/11/2001) than over in the Middle-East and Asia.
Of course, "liberals" in the U.S. want the same thing. Watch as they criticize President Bush for rejecting Bin Laden's offer.