An Australian intelligence agent in Tokyo many years ago was asked what was his nation's essential interest in Japan. Without hesitation, he said: "To keep Japan onside." He explained that his country did not want Japan to slide back into the disastrous aggression of the 1930s and 1940s.

A senior U.S. military officer in Japan said more recently that "U.S.-Japan relations are built on a solid alliance." He added, however, "This is a really high maintenance alliance," meaning that Americans had to nurture relations with Japan daily to prevent Tokyo from sliding back into the passive and pacifist mode that has marked much of the postwar era.

Few today fear that Japan will once again send its armies through China and Southeast Asia to the gates of India. But there is concern that Japan's alliance with the U.S. is eroding because the U.S., notably the Bush administration, has not engaged in the required "high maintenance" to keep Japan "onside" in the political and security game in Asia.

In a study released this week, the Chicago Council on Global Affairs said many Japanese commentators "have worried that the United States is losing interest in Japan. Japanese anxiety about the American commitment to the alliance has grown out of the Bush administration's active (and to many Japanese, unconditional) engagement of North Korea since 2007."

The council asserted: "This new dynamic has evoked memories of 'Japan passing,' a phrase coined during President Clinton's nine-day visit to China in 1998," bypassing Japan. Actually, "Japan passing" has even earlier roots, as when President Nixon pursued normalization of relations with China in 1971 without informing the Japanese.

This long-simmering anxiety in Tokyo appears to have spurred Japan to cultivate its own relations with China. Japan's new prime minister, Taro Aso, said in Beijing 10 days ago, "It is difficult to name other countries as important to Japan as China is."

Japanese leaders have been uncharacteristically candid in expressing dismay over U.S. concessions to North Korea in taking Pyongyang off a list of sponsors of terror. The Japanese have particularly criticized the failure of the U.S. to consult with them. And many have asserted that the U.S. has not supported them in demanding that North Korea come clean on its abductions of Japanese from their own shores.

Japanese political leaders, strategic thinkers and commentators have repeatedly contended that the U.S. preoccupation with the wars in Iraq and Afghanistan, plus what Bush officials call the global war on terror, has left them little time to pay attention to relations with Japan.

Another long-submerged concern, that the U.S. might not defend Japan against attack, has also reappeared, even if behind closed doors. Japanese leaders have asked American officers whether Japan can count on the U.S. to maintain a nuclear umbrella over Japan.

Moreover, Japanese see little to choose between the Democratic candidate for president, Sen. Barack Obama, and his Republican opponent, Sen. John McCain. Neither has said much about Japan during the campaign that, thankfully, will end on Election Day on Tuesday.

The campaign literature for both has been routine boilerplate. Obama says: "The alliance demands, and is deserving of, close political cooperation and coordination at every level, reflecting the key role Japan plays as anchor of U.S. economic and security interests in the region and across the globe."

Similarly, McCain says: "The U.S.-Japan alliance has been the indispensable anchor of peace, prosperity, and freedom in the Asia-Pacific for more than 60 years, and its importance will only grow."

Thoughtful Japanese views can be found in a series of essays published in English by the Japan Institute of International Affairs, a think tank headed by Yukio Satoh, Tokyo's former ambassador to the United Nations.

The removal of North Korea from the list of state sponsors of terror, said Koji Murata, a political scientist at Doshisha University in Kyoto, and the last-minute notification of Japan of that action left Japanese with a "sense of abandonment" on one hand and a fear of being "entrapped" in U.S. strategy on the other. "This," Murata wrote, "is certainly a crisis for the Japan-U.S. alliance."

A strategic thinker, Yukio Okamoto, was pessimistic about the immediate future. "It would be a mistake for Japan to lapse into complacency regarding the expectations a new U.S. administration may have for the security relationship," he said. "A jolt of new activity, if you will, will be necessary to get the relationship off to a good start."

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia. His column appears weekly in Sunday's Focus section.