Revelations that China acquired detailed information about advanced U.S. nuclear weapons, missile guidance systems and other defense technology are causing concern that America will soon lose its decisive military advantage over the world's most populous country. Those worries are unfounded.

This is not to minimize the gravity of last month's allegations by the Cox committee, the select panel of House members investigating reports of systematic Chinese spying in the United States. The committee, headed by Rep. Christopher Cox (R-Calif.), concluded that the secrets the Chinese obtained might allow them to manufacture small powerful warheads to fit on the mobile intercontinental ballistic missiles (ICBMs) they are developing. And those missiles, capable of reaching the United States, could be made more reliable with the help of classified information that may have been improperly provided by Hughes Space and Communications Co. and Loral Space & Communications.

China's ability to strike the United States with nuclear weapons is not new; this has been the case since the early 1980s. Efforts to make its nuclear force more modern, reliable and survivable against attack are normal for a nuclear power such as China, and there is no reason to suppose they demonstrate aggressive intent against the United States. Despite the leaks of defense secrets, the United States will retain more than a 10-to-1 advantage in strategic warheads over China for many years to come. At present, the United States possesses more than 10,000 nuclear warheads of all types, China fewer than 500.

So before we give way to alarm in the wake of the Cox report, we ought to look at a fundamental question: How good is China's military? The short answer is, not very good, and not getting better very fast. Whatever China's intentions, its capacity to harm U.S. interests is severely limited.

Although Chinese defense spending has grown in real terms during the 1990s, it still only totals about $65 billion, according to the highest common estimate. This is less than a quarter of what the United States devotes to its military, though China's armed forces are much larger than America's.

The military investment gap becomes clearer when you look at what the two countries have spent on hardware. The Pentagon owns roughly a trillion dollars' worth of modern military equipment. China's comparable total is less than $100 billion (the American B-1 and B-2 bomber forces alone are worth around $50 billion). China has a large air force, but owns only a few dozen top-line fighters and no intercontinental bombers. By contrast, all 3,000 or so of the U.S. Air Force, Navy and Marines' fighters are of modern technological vintage.

Cut off from the dynamism of the rest of the country's economy, Chinese industries tied to defense are largely bloated and inefficient. Implicitly recognizing these shortcomings, China has reshuffled the organization of its defense industry several times in the past 15 years. According to a Defense Intelligence Agency estimate, only 10 percent of China's armed forces will even have "late Cold War equivalent" weaponry by 2010.

China has by far the world's largest military, with 2.8 million troops--twice the U.S. number. Yet raw size can be deceiving. China has 2 million troops in its ground forces, but the Pentagon estimates that only about 20 percent of them are even able to move about within their own country due to a shortage of trucks and other equipment.

What about the caliber of China's manpower? Again, a recent Pentagon report is revealing. It states that Chinese troops are generally patriotic, fit and good at basic infantry-fighting skills. But it goes on to say that nepotism in the armed forces is rampant, that China's most intelligent and energetic men rarely make a career of the military, and that training remains rudimentary.

Some might respond to these shortcomings by noting that the United States has underestimated Asian armies before. China itself inflicted major setbacks on the United States during the Korean War and could, in theory, be a tough adversary there again. However, we are most unlikely to confront China on the Asian mainland. Today's potential disputes center on the seaways and islands off China's southern coasts. In addition, the armed forces of the United States and its major northeast Asian allies, Japan and South Korea, have improved much more than China's in the last half-century.

Others might argue that China does not need to compete with the U.S. military head-on--weapon for weapon--and could opt instead to challenge U.S. interests through indirect or "asymmetric" approaches. Employing advanced cruise missiles, sea mines, submarines, imaging satellites, antisatellite weapons and electronic warfare techniques, China could wage what its strategists call "local war under high-tech conditions" to target American vulnerabilities--attempting to sink U.S. ships near Chinese shores, or attacking advanced electronic systems on which U.S. forces depend.

There are kernels of validity here--after all, militaries always seek to exploit an adversary's weaknesses. But China will have a very tough time translating such aspirations into capabilities. That is especially true if the United States attends to its own defense by making key systems redundant, hardening them against radiation and taking other precautionary measures.

Moreover, asymmetric warfare can only get you so far. Consider the one area where U.S. and Chinese forces are most likely to clash: in a Taiwan Strait crisis. Should it invade Taiwan to reclaim the island it considers a breakaway province, China's army would need to land enough troops to have a chance of defeating Taiwan's quarter-million-strong ground forces (plus some fraction of its 1.5 million army reservists). It surely would need hundreds of thousands of men for that purpose. But China cannot even move that many forces overland into Mongolia or Vietnam. Its combined amphibious and airlift forces can accommodate only 20,000 troops in all.

What if China tried to simply blockade Taiwan to bring down the island nation's economy and force its capitulation? China would have a better chance of success in this type of operation. But Chinese ships and planes trying to conduct a blockade near Taiwan's shores would remain vulnerable to Taiwanese aircraft. If the United States provided a modest amount of help--for example, a few aircraft carriers to control the air and seaways east of Taiwan (where China would have a hard time attacking them), as well as antisubmarine warfare assets--China could not sustain the blockade and would suffer large losses in the effort.

Or China could barrage Taiwan with ballistic missiles carrying conventional warheads, killing thousands. China forcefully raised that possibility in 1995 when it fired four M-9 missiles into the sea north of Taiwan to express displeasure over a visit to the United States by the president of Taiwan. China has recently quintupled its medium-range missile forces based near the Taiwan Straits. But its ballistic missiles will be hard-pressed to defeat Taiwan's military or sink nearby U.S. ships. Again, China could hurt Taiwan, but could not itself benefit decisively from doing so.

Nothing fundamental about these conclusions will change in the next decade or more. Even leaving aside the United States for a moment, Taiwan may actually get the better of the near-term military competition with China, especially as it gets serious about passive and active missile defenses. It has a more technologically advanced economy than China, and is more willing to purchase weapons from other countries when necessary.

We do not offer these conclusions as an apology for the spy scandals, which resulted from poor U.S. security procedures and a less-than-friendly Chinese attitude toward the United States. The leaks should never have happened, and many of the Cox report's recommendations to prevent future leaks are worthy of implementation. But the military significance of these illicit data transfers has been blown out of proportion, risking excessive and counterproductive policy responses.

There is no doubt that China is a rising power. But it remains a developing country, with per capita income levels only about one-tenth those of the West. It has enormous problems, from farming to banking. China will need at least two decades to become a serious strategic rival to the United States. Meantime, the United States and its major Asian allies need to maintain their composure. Hysteria over the Chinese challenge is the wrong approach, for it creates the potential for inevitable tensions between Beijing and Washington--over Taiwan, human rights and weapons proliferation--to develop into serious crises rather than be patiently handled and gradually resolved.

Bates Gill and Michael O'Hanlon are senior scholars in the foreign policy studies program at the Brookings Institution. A longer version of this article appeared in the current issue of the National Interest.