The dramatic end to Japan's half-century of conservative rule in a late August election led almost immediately to a public spat with the United States. An inward-looking Japan that had reflexively followed the American lead suddenly was no longer an obedient ally.

At a time when the US was trying to woo a recalcitrant China to become a "strategic partner", Japan's insistence on reopening an agreement over US military bases seemed to upset the regional balance. But there are recent signs of a concerted effort on both sides to put underlying strategic interests back in the forefront, propelled in part by the recent eruption of frictions between China and the US.

The row began with the newly elected Prime Minister Yukio Hatoyama's call for more "equal" relations with the US, his advocacy of an East Asian Community à la the EU, and his focus on repairing ties with China. Put together, some saw a nascent urge to abandon the post-war security alliance. A senior State Department official went so far as to tell the Washington Post in late October that the "the United States had ‘grown comfortable' thinking about Japan as a constant in US relations in Asia. It no longer is, he said, adding that ‘the hardest thing right now is not China, it's Japan.'"

The trigger was growing frustration over the Hatoyama government's handling of the relocation of the US Marine air base at Futenma on Okinawa. The Democratic Party of Japan (DPJ) consistently opposed the deal to relocate the base elsewhere within Okinawa, expressing sympathy for the disproportionate burden of the US military presence in Japan born by Okinawans. American officials were loathe to reopen an agreement that had taken years to negotiate and believed the Japanese government exaggerated its domestic political constraints.

At the same time, Japan seems eager to hew its own course with China, to improve relations and begin to build the foundation for a new Asian community. If one is to believe US officials, alarm bells have been ringing among their allies and others in Asia over the rift with Japan. The talk of building a regional organization that might exclude the US made Singapore, Australia, South Korea, the Philippines and even Vietnam worried that this would only aid Chinese ambitions.

Meanwhile, the Obama administration itself was ardently wooing China. President Obama, on the eve of a trip in November, spoke of creating a "strategic partnership." In Beijing, the President avoided public finger wagging. Discussion of difficult issues such as human rights, Tibet and sanctions against Iran were conducted largely, if at all, behind closed doors.

Given their own pursuit of Chinese partnership, American officials could hardly object to Tokyo's efforts along the same lines. In public, they said this is not a zero sum game, that an easing of Sino-Japanese tensions could aid security and stability in the region for everyone. But some US officials soon saw evidence of Sino-Japanese collusion to push the US out of Asia. Privately they pointed to what was considered a telling moment following a trilateral summit of Chinese, Japanese and South Korean leaders in Tianjin in October. Talking to reporters after the meeting, Hatoyama had spoken about Japan's desire to lessen its "dependence" on the US. American officials considered Hatoyama's actions a gross display of obeisance to the Chinese.

Accusations that Japan was drifting into Chinese arms grew louder after DPJ Secretary General Ichiro Ozawa led a group of about 140 lawmakers on an adulatory visit to China in early December. Then Hatoyama and Ozawa raised hackles when they pushed for the Emperor to receive a visiting Chinese senior official, the heir apparent for leadership, Xi Jinping. However, these depictions of Tokyo lurching toward Beijing ignore the gradual evolution of Japanese policy and the deep-seated rivalry that persists.

Sino-Japanese relations reached a low point five years ago after anti-Japan demonstrations were apparently sanctioned by Chinese authorities. Unresolved wartime historical issues drove those outbursts, prompted by Prime Minister Junichiro Koizumi's visits to the Yasukuni shrine, which honors Japan's war dead. Disputes over oil and gas rights in the East China Sea threatened to explode. And China launched a campaign to block Japan's bid for permanent membership in the UN Security Council.

Japanese policymakers began to worry about the impact of these tensions on Japan's growing economic interdependence with China. They were critical of Koizumi's one-sided focus on the US-Japan security alliance.

"To weather the wild seas of the 21st century, Japan's diplomacy must have two elements: the Japan-US alliance and a Japan-China entente," wrote Makoto Iokibe, a defense specialist who now heads the Japanese Defense Academy, in the summer of 2006. "A combination of a gas field accord and a depoliticized Yasukuni issue would provide Japan and China with a clear view for the joint management of East Asia."

Beginning in late 2006, a succession of Japanese administrations has made concerted efforts to repair ties with Beijing and Seoul. Though the atmosphere with China has improved, substantive differences remain. In January, Japan's foreign minister warned that Tokyo would take action if China continued to violate a 2008 deal to develop oil and gas fields jointly. When Ozawa met the Chinese defense minister in December, he said the Japanese see China's military modernization as a threat. Ozawa suggested that if such fears were not eased, Japan might be prompted to undertake its own arms build up.

The Hatoyama government has also moved to upgrade ties, including security links, with Asian powers that share a fear of China, including India, Indonesia and South Korea. Ozawa stopped in Seoul after his visit to China where he apologized for Japan's colonial rule in Korea and pledged to push through legislation granting voting rights to Korean residents in Japan, an issue of great importance to Koreans and opposed by conservatives in Japan.

Recent events seem to have caused the US to reassess its handling of relations in Northeast Asia. There is growing evidence of an emboldened China that seems to interpret America's bid for a strategic embrace with the country as a sign of weakness. The authorities in Beijing took a tougher line toward internal dissent, openly clashed with the US at the climate change talks in Copenhagen, balked at cooperation on sanctions against Iran, and brushed off American protests over evidence of cyber attacks on Western firms.

After all this, America has begun to soften its tone toward Tokyo. Officials pledge patience as the new government looks for a solution to the base problem, while also mounting a public effort to convince Japan that the Marine presence in Okinawa is key to "deterrence" of North Korea and China. There is a renewed emphasis on broadening the security agenda to include other issues, from cyber security to climate change. Hatoyama, too, has emphasized that the Japan-US alliance remains "a cornerstone for Japan to enhance its cooperative relations with other Asian countries, including China."

Whether any real lessons have been learned in Tokyo or Washington remains to be seen. But perhaps the turn in Sino-US relations has reminded people in Tokyo and Washington that there remains a strategic purpose to the alliance.