Now Japan is lending the U.S. support on that potential battle line. Two weeks ago, Washington and Tokyo issued a joint communiqué that specifically cites peace in the Taiwan Strait as a common objective of the two allies. That came just weeks before China's National People's Congress is expected to enact an anti-secession law that may require the mainland to declare war if Taiwan declares independence, and days before U.S. President George W. Bush went to Europe and tried to dissuade the E.U. from lifting its 16-year embargo on selling arms to China—arms that would be most useful for invading Taiwan. As a result, the cross-strait chessboard has become more like a game of go: more subtle and unpredictable. "I do think it was a surprise," says Kenneth Lieberthal, a visiting fellow at the Brookings Institution in Washington and former senior director for Asia at the National Security Council. "If you had asked before, most specialists would have said, 'the Japanese don't do that.'"
That they did is a reflection of Japan's eagerness to reassert itself as an Asian power, its concern about the rise of China, and its traditional ties with Taiwan. The Japanese describe their country's relationship with China as seirei keinetsu—"politically cold, economically hot." Bilateral trade reached $56.8 billion last year, the highest since 2000, but Tokyo is alarmed at China's growing military might. (In its most recent national defense outline, Japan said "attention must be paid" to China's increasing military capabilities.) The joint declaration with the U.S. over Taiwan, says Terumasa Nakanishi, professor of international politics at Kyoto University, "is a warning to Beijing ... that military action toward Taiwan is the one line China cannot cross. Japan cannot back down." Beijing's reaction to the communiqué was appropriately icy: it considers Taiwan a renegade province and reunification (at some future time) is carved-in-marble national policy. Chinese Foreign Ministry spokesman Kong Quan warned that "any irresponsible remarks on China's efforts to enhance national defense aimed at safeguarding its national security and territorial integrity are untenable."
Japan's new stance won't alter the fundamentals of the nearly 60-year cross-strait standoff, and isn't likely to nix what appears to be a minor thaw between Beijing and Taipei. The recent Lunar New Year holiday saw the first nonstop commercial flights between the mainland and Taiwan, and last week Taiwan President Chen Shui-bian made a pact with James Soong, a rival politician who wants better ties with China, not to declare independence, change Taiwan's formal name from the Republic of China, or rule out eventual unification with China.
Tokyo's joint communiqué with Washington, however, puts Japan and Taiwan in a unique, post-colonial bear hug. Japan wrested the island from the Qing dynasty in 1895 and colonized it for 50 years before surrendering it to Chiang Kai-shek's army in 1945. Now the former colonial master is effectively promising to watch-guard its former subjects and their tense relationship with mainland China. If Taiwanese were skeptical or ambivalent, they didn't express it. "The joint declaration is a check on China," says Lai Hsin-yuan, a former adviser to Taiwan's National Security Council. Says Koh Se-kai, Taiwan's de facto ambassador in Tokyo: "We are very happy."