It's as predictable as the rising and setting of the sun: Every time the United States moves to develop a new strategic weapons system that would improve national security, the left starts whining and moaning.

The latest hysteria surrounds the Bush administration's soon-to-be-issued National Space Policy - the first NSP update since the Clinton administration's in 1996. Three years in the making, the new doctrine will reportedly permit the development of weapons to protect U.S. satellites.

Without having seen the final presidential policy decision, the arms-control fanatics are already condemning the new policy with frantic cries of "arms race," "strategic instability" and "militarizing space."

Fretting and fearmongering aside, the fact is that the "final frontier" is critical to our national defense. We'd better make darn sure we maintain our competitive edge there.

Space is the ultimate military high ground - and critical to maintaining the supremacy (in communications, reconnaissance and so much else) of our GIs. It doesn't take a rocket scientist to figure out that whoever holds the upper hand there will hold the upper hand on Earth.

If we don't maintain our space superiority, others, such as the Chinese and the Russians, will gladly replace us - guaranteed.

The "militarization" of space? Already a fact. Hundreds of military-related communications, navigation and intelligence satellites are in orbit, from a number of nations.

The question turns on "weaponizing" space - that is, deploying offensive and defensive space weapons that would protect a nation's Earth- and space-based interests and assets or strike Earth-based targets.

Such Star Wars-like weapons might include ground- or satellite-based lasers or kinetic-energy weapons able to incapacitate (kill) hostile satellites and ballistic missiles en route to their targets. It might also involve space-based hypervelocity metal rods - "Rods from God" - designed to strike ground targets at 7,200 mph (120 miles per minute) with the strength of a nuclear weapon but without the radioactive fallout.

Last month, White House spokesman Scott McClellan told reporters that the Bush NSP actually wasn't considering weaponizing space but would advocate developing means to defend our critical - but now defenseless - space infrastructure from attack. (Left unsaid: R&D on other space systems will surely continue.)

Opponents of the new policy clamor that a space arms race will result from even that policy shift: China, Russia, Japan and even the European Union will surely be provoked into following our lead.

But if we leave the high ground open, what's to stop others from seizing it? The critics' answer: another U.N. arms control treaty.

Arms controllers also argue that space-based weapons are inefficient and expensive relative to conventional weapons.

All these arguments are weak - at best.

A new weapon system will cause an arms race? It ain't necessarily so.

Case in point: For decades, the arms controllers railed against ballistic missile defense, warning that it would grossly destabilize relations with China and Russia and spark an arms race such as the world has never seen.

Yet the Bush administration's initial deployment of missile defense hasn't caused an arms race or made relations with Beijing and Moscow any tougher than they already were. It has, however, improved our national security by providing the first protection against ballistic missiles - ever.

Space weapons more expensive than conventional weapons? Sure, a satellite costs more than a tank. And a tank costs more than a cavalry horse, a rifle more than a rock. The most expensive weapon is the one that doesn't do the job.

What price are the opponents of a more forward-leaning space policy willing to put on U.S. national security?

As for the idea of any treaty preventing the deployment of weapons into space . . . well, tell that to North Korea and Iran - nations undeterred by the likes of the Nuclear Non-Proliferation Treaty.

More, the current U.N. (draft) treaty to prohibit the weaponization of space was introduced by China and Russia - the two nations most active in space today. Only the naive would argue that Beijing and Moscow wouldn't deploy space weapons today if they could. The treaty is merely their diplomatic gambit to buy time to develop their own programs.

That work continues apace. Last year's Pentagon report on Chinese military power says that China, in addition to improving its satellite intelligence and reconnaissance capability, is "clearly working on, and plans to field, ASATs [anti-satellite systems]."

Space is critical to American national security. No nation relies more on space than the United States - and our potential enemies know this.

Failure to protect our space infrastructure would only invite a Pearl Harbor in space, leaving us deaf, dumb and blind - and at war. Maintaining America's military pre-eminence - in space as on land, at sea and in the air - is a necessity.

Peter Brookes is a Heritage Foundation senior fellow.