Usually when foreign policy experts talk about "rising" powers in Asia they mean China. Yet one of the most important recent developments in the region has been Japan's readiness to take new responsibilities for the maintenance of international security. And the centerpiece of this strategy has been the deployment of a Japanese Maritime Self Defense Force flotilla in the Indian Ocean to refuel U.S.-led coalition vessels operating against Al Qaeda and the Taliban.

This week, those ships will start steaming home, not because they have completed their mission, but because the legislation authorizing an extension of their deployment is being blocked by opposition Democratic Party of Japan (DPJ) leader Ichiro Ozawa. Mr. Ozawa hopes the impasse will spark a political crisis in the Japanese legislature, the Diet, and force elections that might give him a shot at power.

Mr. Ozawa argues that Japan's deployment supports a "unilateralist" and "illegal" war by the United States in Afghanistan. He claims that he would be willing to let Japan deploy forces abroad under a United Nations mandate. Of course, convincing the U.N. Security Council to authorize any collective security is almost impossible, and China is particularly unlikely to vote yes for the deployment of Japanese forces abroad.

That suits Mr. Ozawa just fine, since he can point to his internationalism without having to worry about actually sending forces abroad, or upsetting the pacifists and former socialists who form an important wing of his party. Meanwhile, he is doing his best to frustrate the attempts of DPJ realists like Seiji Maehara and Aki Nagashima to reach a workable compromise with the government to keep Japan's forces in the coalition. That, after all, would end the political crisis and allow the government to save face abroad.

Japan's pragmatic prime minister, Yasuo Fukuda, is fighting back. He has been able to blunt charges that Afghanistan is only America's fight, thanks to helpful reminders from leaders like Germany's Angela Merkel and Britain's Gordon Brown that they, too, have troops in Afghanistan. Polls show that 55% of the Japanese public now supports extending the deployment, because they recognize that Japan's reputation is on the line with more countries than just the U.S.

But that support may not be enough. The DPJ's Mr. Maehara has about 50 members on his side so far, but the majority of his party's 222 Diet members are still intimidated by Mr. Ozawa after his huge electoral success in the Upper House election last July. Meanwhile, some of the senior figures in Mr. Fukuda's own Liberal Democratic Party are going wobbly, arguing that it is better to let the legislation die, rather than risk alienating their pacifist allies in the New Komei party by using the ruling coalition's two-thirds supermajority in the more powerful Lower House to ram the bill through.

Washington isn't helping matters either. While the U.S. ambassador to Japan, Thomas Schieffer, has worked hard to convince politicians in Tokyo to pass the legisation, back home the U.S. State Department is rushing to lift North Korea from the list of state sponsors of terror by year's end. Tokyo has objected vehemently to such a move, citing Pyongyang's abduction of Japanese citizens and reminding the Administration of its own promise in 2003 not to remove North Korea from the list until North Korea made progress on the issue. Pyongyang has not been forthcoming at all with Japan, and the possibility that the State Department could delist North Korea anyway would be hugely damaging to Mr. Fukuda's efforts in the Diet, not to mention the Japanese people's overall faith in the U.S.-Japan alliance.

The coming weeks are crucial, but Mr. Fukuda appears to understand the stakes. Twenty years ago, more Americans cited Japan as a threat than the Soviet Union. Fifteen years ago, Japan was criticized internationally for responding to Saddam's invasion of Kuwait by cutting a check and keeping its troops at home. But after Sept. 11 Prime Minister Junichiro Koizumi moved quickly to join the front ranks in the war on terror. Still reeling from the terrorist attacks on the World Trade Center, Americans woke up to see CNN broadcasting the unexpected sight of Japanese ships escorting U.S. Navy vessels.

The effect was transformative. Polling shows that 74% of the American public now consider Japan as a strong ally and focused polls on America's political elite show the number as high as 91%. In London, Canberra, New Delhi and other capitals, governments began rethinking the strategic importance of a Japan that had seemed destined for middle power status. British, Australian and Dutch forces operated with Japanese ground forces in Southern Iraq. In March Australia signed a bilateral security cooperation agreement with Japan, Tokyo's first since the 1960 U.S.-Japan Mutual Security Treaty. The Indian Navy held their first joint exercises with Japan this year.

Much more rides on the current struggle in the Diet than just the fuel being provided by Japanese tankers. The symbolism of Japan's retreat will have a deflating effect not only on the U.S.-Japan alliance, but also on Japan's credibility with other eager strategic partners around the world. Since Mr. Ozawa is unwilling to yield, Mr. Fukuda may eventually have no choice but to force the bill through the lower house of the legislature. But he can win the issue in the court of public opinion before that if he rises above petty domestic politics and calls Mr. Ozawa's bluff, for the sake of Japan's international standing.

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