It would take more time for a missile to get here from North Korea than it took critics to fire off the same tired arguments against missile defense following President Bush's recent speech at the National Defense University.

What those arguments lack in originality, though, they make up in shortsightedness.

For instance, Senate Democratic Leader Tom Daschle contends that "not a shred of evidence" exists "that this works."

Never mind that the Navy has used a fleet air-defense system to protect its planes and ships for more than 20 years -- a system that Pentagon officials say could be easily upgraded to defend against ballistic missiles. Never mind that the two missile-defense tests that did fail last year, as opposed to the eight that have succeeded since 1999, came at the outset of a program that enjoyed a level of support in the Clinton White House ranging from icy detachment to downright hostility.

Basically, the naysayers insist that the United States not commit to missile defense development because there's no working system already on the shelf. By the same token, JFK was foolish to commit the nation to landing a man on the moon within 10 years. "Pie in the sky," they would scoff. "There's not a shred of evidence that anything can break free of earth's gravity, let alone go to the moon."

Like JFK, President Bush has pledged to commit America's best minds to making this next-generation science program work. And the pessimists forget that America's best minds rarely encounter a challenge they can't overcome. For example, NASA scientists recently landed a space probe on a small asteroid some 196 million miles from earth. Yet we're to believe hitting "a bullet with a bullet" is impossible?

So some critics, such as CNN's Bill Press, switch gears and question the success rate. If a country launched 100 missiles at us and we could stop only 95, they say, that would be unacceptable, so why try?

By that reasoning, if someone devised a program that enabled 95 percent of America's uninsured to afford health coverage, we would reject it because it left the remaining 5 percent no better off. And we would forget about putting locks on our doors and windows, since there is always a criminal or two who would be able to get through anyway.

But isn't a 95 percent success rate against missile attack better than the zero percent we've got now?

Then there's House Minority Leader Richard Gephardt, who proclaimed the president "is jeopardizing an arms control framework that has served this nation for decades."

One problem: The "arms control framework" he's referring to -- the 1972 Anti-Ballistic Missile Treaty -- stopped "serving" us about 10 years ago, when the Soviet empire crumbled. The geopolitical scene has changed radically since then. Our primary concern is no longer Russia or China. Today's challenge is to defend against accidental strikes or attacks from irresponsible rulers of rogue states such as North Korea, Iran or Iraq.

Other critics say America's missile defense will lead to proliferation. But they have it backwards. Not having missile defense has led rogue states to work vigorously to develop weapons of mass destruction. They see our lack of a missile shield not as an invitation to disarm but as a vulnerability to exploit.

New ideas can be tough to accept, and what President Bush is proposing is indeed a new way of looking at security. The rogue states, he notes correctly, have changed the nature of nuclear threats. No longer can we base our defense on "Mutually Assured Destruction." The Saddam Husseins and Kim Jong-Ils of the world have no respect for the concept. To them, retaliation is a problem for their citizens to deal with. And considering that one has chemically gassed his subjects and the other has starved millions of his to death, it's unreasonable to think concern for the average citizen matters much to either one.

The only answer now is to render their weapons useless -- not just against the United States but against our allies and others around the world. That's why we should join with Europe, with Russia, with the rest of the Americas and with our friends in Asia to replace one MAD -- Mutually Assured Destruction -- with another: Mutually Assured Defense.

And, like our critics, to move quickly.

Jack Spencer is a defense policy analyst in the Davis Institute for International Studies at The Heritage Foundation, a Washington-based public policy research institute.