Fuel to the Fire; Rising tensions with China may add impetus to Japan's gradual shift to a more assertive military.

Byline: Christian Caryl (With Hideko Takayama and Kay Itoi in Tokyo)

Few world leaders can pass up the temptation of a nice photo op with the men and women in uniform, and Junichiro Koizumi is no exception. So there was the Japanese prime minister last week, looking his dashing best in bright fall sunshine, as he prepared to commemorate the 50th birthday of his country's postwar military by reviewing a procession of 4,000 soldiers, complete with attack helicopters, heavy tanks and armored personnel carriers. But none of those heavy arms was in evidence as the parade got started; in the lead instead was a phalanx of water trucks--symbols of the Army's devotion to disaster relief.

It was one of those self-effacing moments that the Japanese have come to expect from the Self-Defense Forces, or SDF. Yet, ironically, Koizumi's visit to the troops comes at a moment when Japan's military is on the cusp of some of the most significant changes in recent memory. Koizumi and his political colleagues--many of them members of a generation that doesn't feel unduly burdened by the legacy of the second world war--are laying the groundwork for an overhaul of their country's defense strategy, one that would give the SDF more of an offensive orientation.

What's making the process--which has been maturing steadily since Koizumi took office in 2001--more urgent are rising tensions between Japan and its behemoth neighbor China. The two countries have sparred for years over disputed territory and the unresolved legacy of World War II, but more recently have become economic and energy rivals. China is worried about U.S.-Japan cooperation on missile defense, fearing the technology could be shared with Taipei. A recent incursion into Japanese territorial waters by a Chinese sub has aggravated rising nationalism on both sides. Last Sunday, Koizumi and Chinese President Hu Jintao met at the APEC summit in Santiago, Chile, to soothe feelings--but it's clear that Japan's pre-eminence in East Asia is being challenged by a powerful upstart. North Korea has always worried Tokyo; now the perceived danger from China is upping the ante.

Japan's reaction to the Chinese sub incident was, by Asian standards, forward-leaning: it named the culprit, demanded a public apology--and got one. "For the first time, we're actually pointing out that it's a Chinese sub," says foreign-policy expert Jitsuo Tsuchiyama of Aoyama Gakuin University in Tokyo. "These sorts of things are new in Japanese policy." Not long after the Chinese expressed their "regret" over the incident, Japanese newspapers were bruiting a more proactive possibility: that the Japanese Navy might set up a forward base on a strategically sensitive island in the area to keep an eye on future incursions. (The Japanese Defense Agency has denied the rumor.) "In the past the government was always worried about negative reactions from China," says Masashi Nishihara, president of the National Defense Academy, the elite war college for the Japanese military. "But now the government is bolder. That's a new development. We have to be a little more assertive."

China is not the only problem; the threat of a nuclear-armed North Korea remains. The larger concern is that North Asia is an increasingly unpredictable strategic neighborhood, especially as the United States gradually eases its military footprint in the region. In stark contrast to Europe, where the Great Power rivalries of the cold war have been dissolved into the EU and NATO, Japan and its neighbors are still basically at daggers drawn. "Northeast Asia has no ...