Koizumi's ability to sustain the mission in Iraq for as long as he did reflects a delicate political balancing act. Japanese troops were posted in a relatively peaceful area near the southern Iraqi city of Samawah. Their assignment, the Japan Defense Agency explained, focused on "humanitarian and reconstruction assistance" and was "designed solely to help the people of Iraq in their attempt to rebuild their own country." The Japanese safe-haven was essentially carved out by Dutch, and later British and Australian, combat forces.

Koizumi sensed that satisfying the United States, even if it meant risking the lives of Japanese soldiers, was a fair bargain just so long as those risks didn't materialize into actual casualties. Although the prime minister's advocacy of the JSDF mission in Iraq did not hurt him politically, it would have been far harder for Koizumi (or any future Japanese leader) to maintain such a stance if Japanese troops were subjected to the chaos and violence that confronts American forces every day. If the Japanese public was genuinely supportive of the mission, if the deployment revealed a sense of shared strategic purpose or was seen as advancing genuine Japanese national interests, then the Japanese mission in Iraq would have been both useful and significant. As it was, the troops were merely symbolic. Koizumi's decision to risk some political capital, as well as time and attention, rallying a modicum of public support for an exceedingly modest, even token, military deployment seems a case of misplaced priorities.

These sentiments are reflected in public opinion polls that show the Japanese wanting to be actively engaged in world affairs, but more focused on challenges and threats in East Asia than the Middle East. In April 2005, the Mainichi Shimbun, echoing public sentiments, warned that the prime minister was not "making sufficient effort to improve Tokyo's relations with Beijing and Seoul." In other words, Koizumi invested his attention, and Japan's military resources, in a distant operation in Iraq, even as the Japanese public remained focused on genuine security issues much closer to home.

It is for this reason that the Iraq case should be seen as an anomaly, not as a harbinger. U.S. pressure on Japan to become involved in peripheral, out-of-area missions could lead to tensions in the alliance, particularly while regional threats fester and grow.

Take, for example, the case of North Korea. The leading regional security challenge of the past decade has been created by the Clinton and George W. Bush Administrations' inability to prevent North Korea from developing offensive military capabilities, including both nuclear weapons and the ballistic missiles that could some day deliver these weapons to Japan or beyond.

The Democratic People's Republic of Korea's (DPRK) various weapons programs have been of concern for Americans for some time, but they pose a far more urgent threat to Japan. Furthermore, the Japanese have still other reasons for distrusting Kim and his duplicitous regime: the DPRK refuses to account fully for the abduction of Japanese citizens in the 1970s and 1980s. Continued strong opposition within Japan to the use of the military for offensive ends suggests that unilateral pre-emptive action by Japan against North Korea, for example, is highly unlikely. On the other hand, it is unrealistic to expect that Tokyo would wait for U.S. permission to respond to a direct attack. It is only slightly more plausible that the Japanese would refrain from using force in response to credible evidence of an imminent threat.

Following the North Korean missile test in July, chief cabinet secretary, Shinzo Abe, a leading candidate to replace Koizumi as prime minister, hinted that the constitutional restrictions on the use of force would not prevent Japan from waging pre-emptive attacks against North Korean missile sites. "If we accept that there is no other option to prevent a missile attack", he told reporters, "there is an argument that attacking the missile bases would be within the legal right of self-defense. I think we need to examine this from the perspective of defending the Japanese people and nation."

Short of pre-emptive strikes, a Japanese military, operating independently of the United States, could deter North Korea from attacking Japan. An independent and empowered Japan might also succeed in convincing the DPRK to abandon its nuclear ambitions. The potential gains are speculative and Japan's actions will still be constrained by the anti-militarist impulses of the Japanese public, but the prospects for a more credible deterrent or threat coming from a "normal" Japan should be considered relative to U.S. economic and diplomatic pressure, which has been completely ineffective in halting North Korea's bellicosity.

Japanese military power might prove instrumental for dealing with future, more serious challenges to the regional security order. Japan's lingering hostility toward and suspicion of North Korea in the near term pales in comparison with its medium- to long-term concerns of a rising China. The trajectory of China's rise to regional prominence threatens to collide with both Japanese and American interests. The open question is whether all three countries will be able to establish a new strategic balance or whether competition for influence in East Asia will lead to a clash that could threaten the lives of hundreds of millions of people on both sides of the Pacific.

Common economic interests within Asia may lead to China's peaceful integration into the region. Or China could turn away from its current course of political and economic liberalization and revert to economic autarchy imposed by military force. It is even possible that China could become a revisionist power, no longer content to accept regional security configurations in their present form. That could occur even if the PRC holds to a course of economic reform.

Against those unlikely but dangerous possibilities, Japan's neighbors should welcome a potential counterweight to a rising China. Many already do. Attitudes toward Japan vary widely, with Taiwanese, Singaporeans, Filipinos and Malays much more favorably disposed than are Koreans to the notion of a wider security role for Japan. These attitudes could evolve further if China's behavior grows more threatening.

The decades-long U.S.-Japan strategic partnership is changing. Americans are becoming increasingly anxious about the costs and risks of our permanent global military presence. We welcome changes that will allow the U.S. military to step back from its role as the world's policeman, and are looking for ways to devolve security responsibilities and reduce our risk exposure. The Japanese--while retaining a strong anti-militarist disposition--are willing to play a more assertive role. They are anxious for their country to behave, and to be treated as a normal country, that is, as a country responsible for defending its interests. Japanese Self-Defense Forces are already highly capable, and Japanese military capabilities could quickly expand if the security environment grows more threatening.

Japan is a stable and mature democracy. The pre-World War II era, when an imperial Japan attempted to secure an exclusive economic sphere for itself, is long past. The ghosts of World War II cannot be allowed to forever dictate the shape and character of U.S.-Japan relations. Americans and Japanese should welcome a transition away from a patron-client relationship, to one based on shared interests, mutual trust and understanding.