Now that it appears all but certain that a missile defense designed to protect the United States and its allies will be built sooner rather than later, congressional opponents are resorting to a new (and desperate) argument: We can't afford it.

Senate Majority Leader Tom Daschle in particular has been very critical of the fact that President Bush's proposed budget for 2002 calls for a 57 percent increase in spending for missile defense.

It sounds expensive, until you realize how underfunded missile defense has been. President Clinton had little enthusiasm for it, and his budgets reflected this. Now, finally, we have an administration that recognizes the threat posed by ballistic missile programs in Iran, Iraq, North Korea and other states -- one that seeks to put its money where its intentions (and, not incidentally, U.S. law) dictate.

Look at the numbers another way. Yes, $8.3 billion represents a 57 percent increase in missile-defense spending. But it's also only 2.4 percent of the $343.3 billion requested for all defense needs, and a mere .04 percent of the entire $1.98 trillion budget. That's hardly a "budget buster," as critics of missile defense like to portray it.

Consider, too, that lawmakers have packed a record amount of "pork barrel" spending into the proposed budget bills, including $18.9 million for the Puget Sound commuter rail project in Sen. Patty Murray's state of Washington, $20 million for "railroad rehabilitation" in Sen. Ted Stevens' Alaska, and $1 million for the Tuscaloosa City Riverwalk and Parkway development in Sen. Richard Shelby's Alabama.

All together, we're talking about nearly 19,000 in-district projects worth a combined $280 billion. Yet we can't spare a small fraction of that amount for a project as vital as missile defense?

And make no mistake -- it is vital. Sen. Daschle refuses to support the missile defense appropriation because it would "cannibalize the personnel and force structure that deal with the threats we are likely to face." He calls missile defense "the most expensive possible response to the least likely threat we face."

With all due respect, I must ask: Has the senator picked up a newspaper lately? Nearly every day, we learn of another ballistic missile test or the sale of missile technology to countries that are hardly allies of the United States.

North Korea has fired a missile over Japan into the Pacific Ocean. Iran has used its plentiful oil revenues to purchase missiles and missile technology from Russia and China. Most experts sense Iraq has resumed and reinvigorated its chemical and weapons-of-mass-destruction programs. Not to mention Syria, Libya, Sudan and other states where hostility toward America has become the largest line-item in the budget. The world is indeed getting smaller, and few things illustrate this as clearly as the proliferation of missiles capable of letting a poor nation such as North Korea strike U.S. shores with devastating power.

And please, let's hear no more about the Anti-Ballistic Missile (ABM) Treaty. Even those who can't accept that it died in 1991 when the Soviet Union -- one of its two signatories --ceased to exist have to admit that its usefulness as a guarantor of world peace has long since passed.

The Soviet Union, after all, was predictable. And it was our knowledge of how they would behave in crisis situations that allowed "Mutually Assured Destruction" to work. They knew they couldn't destroy the United States with nuclear weapons without themselves being destroyed.

But Cold War deterrence no longer applies. The Soviets are gone, and the United States is facing far more unpredictable adversaries. We don't know what North Korea's Kim Il-Jong or Iraq's Saddam Hussein would do with a nuclear-tipped ICBM. But we do know they're on a fast track to acquiring that capability.

This whole debate shouldn't boil down to a zero-sum game, anyway. Why is it missile defense or troop readiness? Why not both? It took money for President Reagan to rebuild America's armed forces in the 1980s, but it was that investment that allowed America to become the pre-eminent military and geopolitical power on earth.

The irony is that Congress already has made it U.S. law to build a missile defense "as soon as is technologically possible," to quote the National Missile Defense Act of 1999. But that requires money. Call it a "commuter rail project" if you must, but let's begin funding missile defense as if it's a matter of life or death -- because, frankly, it is.

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.