Updated

What if?

We now know that if a terrorist gets his hands on a nuclear, biological or chemical weapon, he would not hesitate to use it on America.

And we now know that another major terrorist attack is not only "possible" but, according to our top officials — Vice President Cheney, Defense Secretary Rumsfeld, Homeland Security Chief Ridge — it is inevitable.

OK, but then why are we no longer on the offensive in the war against terrorism? Why then are top U.S. military brass leaking to The Washington Post how the Bush administration cooled on removing from power the world's likeliest supplier of weapons of mass destruction to terrorists: Saddam Hussein? And how is it that the Bush administration only now understands the "difficulties" of such a military operation (against a pathetic military that we whipped a dozen years ago and is one-third the size it was then)?

The ongoing Washington flap about what the Bush administration knew before Sept. 11 and how it acted on such information — relatively lackadaisically — is somewhat understandable in context. After all, before Sept. 11, few could stretch their imagination to answer: "What if Arabs from U.S. flight schools hijacked commercial planes to slam them into key U.S. monuments?"

Indeed, such a lack of imaginative leap is responsible for key intelligence failures throughout history. Stalin could not imagine "what if" Hitler were to launch an unprovoked attack against a fellow totalitarian dictator in June 1941. Franklin Roosevelt could not imagine "what if" imperialist Japan were to attack our Pacific fleet that December. Jimmy Carter could not imagine "what if" the mighty Shah of Iran were to crumble when a hysterical cleric returned from exile in 1979.

Looking back, we may lament the imagination gap that produced some of these intelligence failures. But we understand them.

And even if some exceptionally imaginative people opened their minds to such leaps, who else would believe them? Would the U.S. government have poured the resources and switched its focus so sharply at the end of last year on the basis of this new imagined threat? Our new approach to domestic security and our launching the war against terrorism could not have happened had we not been attacked.

But that's then, and now's now.

Now, we can imagine "what if" terrorists got their hands on a "loose nuke." Anyone still having trouble should head for the mall and watch Ben Affleck and Morgan Freeman in the Tom Clancy thriller The Sum of All Fears. And just last Sunday, the prestigious New York Times Magazine had blasted across its cover the following frightful sentence: "The best reason for thinking that a NUCLEAR TERRORIST ATTACK [their emphasis] won't happen is that it hasn't happened yet, and that is terrible logic."

Inside, ace reporter Bill Keller ends his careful and lengthy examination: "A terrorist who pulls off even such a small-bore nuclear explosion will take us to a whole different territory of dread from Sept. 11. It is the event that preoccupies those who think about this for a living ..."

Now everyone can imagine "what if."

That removes any excuse our government may have for not acting on the threat. It is clear, and it is present. Any reasons for the Bush administration's pre-Sept. 11 lackadaisical attitude are gone.

So what are we waiting for in the war against terrorism? Why are we allowing the prime prospect as terrorist-supplier, Saddam Hussein, to further build up his arsenal bulging with weapons of mass destruction? Every day that passes risks the mega-attack against America imagined in current movies and articles.

Should that happen — God forbid! — there can be no excuse by George W. Bush. His presidency would be as devastated as parts of America. For he — and all of us — by now know "what if."

Kenneth Adelman is a frequent guest commentator on Fox News, was assistant to U.S. Defense Secretary Donald Rumsfeld from 1975 to 1977 and, under President Ronald Reagan, U.N. ambassador and arms-control director. Mr. Adelman is now co-host of TechCentralStation.com.