Perhaps blinkered by its focus on the immediate threats from the Middle East and North Korea, America is passively allowing a very dangerous course of events to unfold elsewhere, in another region vital to our national interests. Unless we awaken, and take action, we may someday find ourselves facing an even more formidable set of problems than our current struggle for survival in the War on Terror.

In April I traveled to Beijing to deliver a paper on "'Command of the Sea' and the Proliferation Security Initiative" at an annual symposium on maritime security held by the Ford Foundation and the China Institute for Contemporary International Relations. I left China troubled about the future of the Asia—Pacific region. Why? For what might seem like an odd reason: Many influential naval strategists in China today are followers of Alfred Thayer Mahan, the influential maritime thinker of the Theodore Roosevelt era.

That could portend friction in the Asia—Pacific region or, in the extreme case, military conflict.

It's happened before, when Kaiser Wilhelm II, Admiral Tirpitz, and other German luminaries launched their country into a disastrous naval competition with Great Britain, the preeminent maritime power of the day. Not only did Mahan —— the second president of the U.S. Naval War College and one of the principal architects of the U.S. naval buildup in the 1890s —— focus the attention of students of sea power on critical points on the map, but he also told them to prepare for titanic naval battles, which for him were the sine qua non of naval warfare.

Speaker after speaker at the Beijing symposium quoted Mahan's dictum that "command of the sea" was defined as "that overbearing power on the sea which drives the enemy's flag from it, or allows it to appear only as a fugitive; and which, by controlling the great common, closes the highways by which commerce moves to and fro from the enemy's shores."

This enthusiasm for Mahan and "overbearing power on the sea" converges with another development that barely registers on the American agenda: incremental Chinese expansion in the South China Sea. Chinese claims to several islands in the region could threaten the flow of maritime commerce through the busy Strait of Malacca. Despite its oft—proclaimed commitment to freedom of navigation and its extensive maritime interests in the region, the United States has publicly soft—pedaled the issue. If public statements accurately represent strategic thinking, America needs to remedy this shortfall in its Asia—Pacific strategy.

In recent decades China has acted at opportune moments to acquire strategic outposts allowing it to assert control over the waterways of the region. In 1974 Chinese forces wrested the Paracel Islands from a teetering South Vietnam. In 1988, taking advantage of united Vietnam's pariah status, the Chinese navy pummeled a Vietnamese flotilla and occupied several of the strategically placed Spratly Islands. In 1995, following the U.S. withdrawal from the Philippine Islands, Beijing capitalized on American inattention and Filipino weakness to seize control of Mischief Reef, an islet located within the 200—mile exclusive economic zone of the Philippines.

These moves came when great—power —— especially American —— opposition was unlikely. They also signaled China's willingness to use naval force to back up its maritime claims.

In 1998 China moved to consolidate its control over Mischief Reef by constructing permanent military facilities there and elsewhere in the Spratlys. This chain of events represents an attempt by China to extend its outer defense perimeter, establish bases flanking vital sea lines of communication, and ultimately assert a measure of control over the approaches to the Strait of Malacca, which empties into the South China Sea.

A corollary is Beijing's long—term goal of excluding the United States from the region and consolidating its status as the foremost power in Asia, consonant with the ancient "Middle Kingdom" concept. Accordingly, China has used its new insular possessions to bolster its long—standing claims to most of the South China Sea —— claims that in 1992 were codified in PRC domestic law. If left unopposed, China's creeping expansion would place it squarely athwart the crucially important sea lanes. Naval and air bases on Chinese—occupied islands could disrupt maritime traffic that carries one—sixth of the world's trade and over 70 percent of Japan's oil. Allowing China to control Japan's lifeline would set a dangerous precedent.

Evidently for the sake of Chinese cooperation vis—à—vis North Korea, the Bush Administration has telegraphed its preparedness to overlook a policy that may eventually ratchet—up tensions in a region of vital U.S. interest. Washington's neglect may encourage further seizures of territory and claims to an even wider swath of the waters in China's geographic environs. The United States, then, is condoning actions that could backfire against its own security interests and those of its friends in Asia. Its passivity may be ceding the South China Sea to Beijing as a sphere of interest —— certainly an unpalatable result from the American standpoint.

From time to time, some China—watchers have urged Washington to take a hard—line stance against Chinese maritime encroachment. However, it would also be undesirable to antagonize China to the detriment of the long—term bilateral security relationship. Rather, U.S. policymakers should formulate a policy that lies somewhere between the poles of militant opposition and inaction under the guise of "comprehensive engagement" —— the mantra of the Clinton administration.

American success in the 1996 Taiwan Straits showdown suggests a useful approach to the South China Sea question. On that occasion the Clinton administration mounted an impressive display of naval force, dispatching two aircraft—carrier battle groups to the area to underwrite its public rhetoric. Beijing backed down in the face of this firm response meshing force and diplomacy. This was a turning point in U.S.—China relations, reversing several years of policy drift by Washington.

A similar program of tactful diplomacy, backed by displays of continuing U.S. naval supremacy, would demonstrate U.S. resolve in the South China Sea today. First, during future meetings with Chinese dignitaries, U.S. diplomats and defense officials should underscore America's opposition to Chinese claims in the region —— helping dispel the appearance of tacit consent that has typified U.S. policy in the Asia—Pacific region.

Second, to support U.S. diplomacy, the Seventh Fleet should vigorously pursue Freedom of Navigation operations in the South China Sea and the Strait of Malacca. A highly visible naval presence in Chinese—claimed waters would provide tangible evidence of America's refusal to acquiesce in Chinese expansion —— lending credence to the rhetoric of diplomats.

Third, U.S. scholars and officials should try to nurture a more sophisticated understanding of Mahan among their Chinese counterparts. Mahan emphasized peaceful commerce as much as he did apocalyptic fleet engagements. Far from being natural competitors in the Asia—Pacific, destined for a Trafalgar in the South China Sea, the United States and China have a joint interest in quelling piracy, terrorism, and weapons proliferation at sea, which endanger prosperity in both countries. That's especially true now that China relies on the sea lanes to supply it with the oil and raw materials needed to support a surging economy.

Fortunately, the United States has time. China will be on its best behavior as it pursues economic development and readies itself for the 2008 Beijing Olympics. And the Chinese navy remains weak for now, so the Bush administration and its successors may be able to influence not only the Chinese naval force structure but, more importantly, the thinking of the naval officers who will command the Chinese fleet as it grows in strength. Maritime conflict is not a foregone conclusion.

International relations abhors a vacuum. Firm diplomacy, scholarly and official exchanges, and a highly visible military presence would remind Beijing that, while the United States has no desire for a confrontation in the South China Sea, neither will it permit Chinese expansion at the expense of its allies and its interests. Having made that point, Washington can seek cooperation with this rising Asia—Pacific power.

A former U.S. Navy surface warfare officer, James Holmes is a senior research associate at the University of Georgia Center for International Trade and Security and an adjunct professor of strategy at the U.S. Naval War College.