The "event" will not happen in the US and it won't be an act of "terrorism" in the al-queda sense. It will happen in Iraq.
Either a US or British plane patrolling the fabled "no fly zone" will be shot down, or the inspectors will find some other "undeclared" weapon.
Bush will then go on TV and browbeat the United Nations until they meltdown and authorize the US to use all "necessary force" to "disarm" Hussein. Only the French will make some inconvenient objections but they, too, will fold.
By the way, I'm STILL waiting to read somewhere in the media (or hear it discussed) WHERE those empty chemical warheads they found last week originally came from.