THE THOUSANDS of angry protesters who took to the streets in anti-Japanese demonstrations last weekend in Beijing and southern China - with, of course, the tacit approval of Chinese authorities - reflect dangerously rising Sino-Japanese tensions that are no mere sideshow for Americans.
The United States has a deep interest in peace in this region, specifically in seeing neither a remilitarized Japan nor an aggressively expansive China. But the U.S. invasion of Iraq has hastened a decided weakening of Washington's long dominance in East Asia - leaving a power vacuum in which a China rapidly gaining strength vies for primacy with Japan.
World War II in the Pacific was rooted in conflict between these two age-old rivals, in part driven by Japan's thirst for resources. Another such war - fortunately, not yet a real prospect - could be driven by China's quest for energy supplies. This time, too, the United States inevitably would be drawn in - though on the side of its World War II enemy turned close ally, Japan.
That mustn't happen. China's vast labor pool and Japan's advanced technology are a highly complementary economic pairing that, in recent years, has been increasingly profitable for both sides of the East China Sea. Yet political relations have soured as the natural product of the raw nationalism - and militarism - spawned in both nations by their respective ruling parties. And this face-off could get a lot more bitter.
Despite apologies of sorts from Tokyo over the years, China's anger over World War II has been energized by Tokyo's moves to expand its long-limited military capacities, Japanese school texts that don't adequately portray Japanese war atrocities in China, and the annual visits in recent years by Japan's prime minister to a shrine that pays homage to its war dead, including certain war criminals.
In turn, Japan fears an emboldened China that is investing heavily in its military abilities, that has overtaken Japan as the world's No. 2 oil importer, that could potentially control some of Japan's vital shipping lanes if it takes over Taiwan, that opposes Tokyo's desire to become a permanent member of the U.N. Security Council, and that eventually could dominate the Japanese economic powerhouse.
Both sides increasingly are drawing firm lines in their quarrels over certain sections of the East China Sea that may hold oil or gas reserves and that are the most likely spots for clashes between the two.
With the Iraq war and tensions on the Korean peninsula and between China and Taiwan grabbing the headlines, this is one hot spot in Asia's latest iteration of the Cold War that calls for more U.S. attention. Washington and Beijing recently agreed for the first time to hold regular high-level strategic meetings, and the deteriorating state of Sino-Japanese relations ought to be on that agenda. Likewise, while a forceful Japan may serve some U.S. interests, the risks of that ought to push Washington to more actively discourage Tokyo's renewed militarism.