The Cold War's most successful arms control agreement is imperiling U.S. forces and increasing the probability of a conflict in Asia.

The U.S.-Soviet Intermediate-Range Nuclear Forces (INF) Treaty contributed to stability in Europe during the Cold War's final years by eliminating both nuclear and conventionally armed ground-launched cruise and ballistic missiles with ranges of between 500 and 5,500 kilometers.

Now, however, the treaty is preventing the U.S. and Russia from responding to a growing threat from China, which has been expanding its missile force at an unparalleled rate. China now has at least hundreds of ground-launched intermediate-range missiles. By comparison, Russia and the U.S. have none.

The last time Americans worried about a "missile gap" - a phrase consigned to history along with the Soviet Union - Gerald Ford was U.S. president, Berlin was a divided city and Taiwan was a U.S. treaty ally. With the Cold War's end and the emergence of a unipolar era, Americans, it was supposed, no longer needed to worry about comparing numbers of tanks, bombers and missiles.

"20 years after the Soviet Union's dissolution, the U.S. is once again facing a missile gap, and unlike the missile gaps of the Cold War, there is no question as to this one's existence." --Michael MazzaBut while Washington and Moscow were busy eliminating entire classes of missiles and with good reason, on the other side of the Eurasian land mass Beijing was investing in missile technology. Today, missiles play a central role in Chinese military strategy. And so, 20 years after the Soviet Union's dissolution, the U.S. is once again facing a missile gap, and unlike the missile gaps of the Cold War, there is no question as to this one's existence.

Why does this matter? The U.S.-China missile gap (and the Sino-Russian one, as well) creates strategic instability in a way that the perceived Cold War missile gaps never did. With its ground-based missiles, China can target U.S. and allied bases in the Asia-Pacific as far away as Guam, including key U.S. facilities in South Korea and Japan.

With its new anti-ship ballistic missile, also ground-launched, the People's Liberation Army will likewise be able to attack U.S. aircraft carriers and other capital ships at sea.

Because the U.S. cannot field intermediate-range missiles, it could not respond in kind to a missile strike on regional assets. Instead, it would have two options. It could rely on tactical fighters to carry out retaliatory strikes. Or, it could rely on longer-range options such as bombers or prompt global strike munitions (basically, conventionally armed intercontinental-range missiles).

Given Russia's lack of intermediate-range missiles, it would have similar options in responding to a Chinese missile attack.

The first option is highly escalatory because it involves an infringement of Chinese territorial integrity by a presumably large fighter force. It puts a higher number of American lives at risk and would engage a wider array of Chinese forces than a simpler tit-for-tat retaliatory missile strike. And reliance on tactical aircraft to respond to Chinese missile strikes could be problematic because those strikes might well have rendered U.S. airbases and aircraft carriers unusable, or worse.

Option two is potentially even more escalatory. Bombers and long-range missiles, after all, look an awful lot like nuclear delivery vehicles. China might very well be incapable of determining with what an incoming bomber or missile was armed. It is an open question whether Beijing would wait to find out before deciding how to respond.

Fortunately, the solution to this conundrum is quite clear. First, Washington and Moscow should invite Beijing (as well as other Asian states) to accede to the INF Treaty, or some updated version of it. If the Chinese decline the invitation, Russia and the U.S. should agree to abrogate the treaty while also agreeing to keep Europe free of those weapons, where a missile buildup would needlessly destabilize a largely stable region.

The U.S. military, and the Russian military if it desires, should then begin a spirited buildup of its own ground-based intermediate-range missile force in Asia.

Although counterintuitive, this would contribute to strategic stability. By developing more options for proportional responses to a Chinese military strike, the U.S. military would make escalation management an easier task, thus making vertical escalation much less likely. Such a move would also give Beijing incentive to sign up to a new INF treaty, as the value of its own missiles would be greatly diminished by a balanced U.S. missile force.

If other Asian states begin fielding theater-range ballistic missiles in large numbers as well - a likely scenario given their affordability and obvious merits - the need for a regionwide INF treaty would become apparent even to the Chinese.

But unless and until the U.S. narrows its missile gap with China, stability in Asia will continue to erode.

Michael Mazza is senior research associate at AEI.