US President Barack Obama's maiden visit to Japan on Friday is important not only for Washington-Tokyo ties, but also for the rest of the world, especially Asia.

Obama and Japanese Prime Minister Yukio Hatoyama both have come to power by using "change" as their slogans. The two have promised to "change" their domestic political and social environment, but people are now eager to see if they will bring about any "change" in US-Japan ties, too, and how do they plan to further consolidate their alliance.

Obama and Hatoyama, to be sure, discussed bilateral relations when they met in New York last month, but it's in Tokyo that they are expected to come up with decisions. And those decisions hold special significance for the international community, especially Asian countries.

In 2001, when George W. Bush and Junichiro Koizumi assumed office in the US and Japan, the international community was worried about what the two "hawks" would do. And their policies later proved that those worries were not unfounded.

The talks between Bush and Koizumi were always smooth, and the two usually coordinated tacitly to take strategic decisions. When the New Conservatism theoreticians in the US suggested establishing an "Alliance of Democracies" in the Asia-Pacific region - aimed mainly against China -Taro Aso, then Japanese foreign minister, announced that he was ready to found the "Arc of Freedom and Prosperity".

Some Japanese Liberal Democratic Party (LDP) leaders believed (and still believe) that as long as Japan complied with American strategy and cemented its alliance with the US, all other diplomatic issues could be solved easily irrespective of its "souring political relations" with China and the Republic of Korea (ROK). As time passed by, peoples in the US and Japan condemned the policies of Bush and Koizumi by voting them out.

Today it is generally believed that Obama and Hatoyama have embraced a pragmatic or moderate approach. They are "doves", as opposed to the "hawks" that were Bush and Koizumi. If the two "doves" maintain their positions, they will truly facilitate peace and development in the Asia-Pacific region and the world beyond.

But the US and Japanese policies show that they still have many differences, some of which even concern their national direction and strategy.

To "reinstall the US as the world leader", the Obama administration has stressed right from the beginning that it needs not only "allies", but "new partners", too. And Obama has declared that Sino-US relations are "the most important bilateral ties in the world".

That may sound a bit of an exaggeration, but the least it indicates is that Sino-US ties could enter a new stage, and that Japan's importance as an American ally might recede. The China-US-Japan triangle, in which Japanese "hawks" have long pursued the policy of "the US and Japan vs China", is slowly evolving into a formation favoring China.

Although Hatoyama has promised Obama that Tokyo would remain Washington's "close" ally and stressed the importance of their alliance, the new Japanese Cabinet wants to reshape US-Japan ties and establish a "more equal relationship". Hatoyama has said Japan should become a "bridge" linking Eastern and Western, and wealthy and poor countries to win the respect of the international community.

Against Japan's previous sluggish regional policy, Hatoyama has proposed to establish an East Asian community (EAC), underlining that Asia is the "survival region" for his country. Although he said an EAC "will not exclude the US", he didn't spell out in what capacity it would be part of the regional grouping. This is contrary to Washington's intention of setting up an "APEC community".

Moreover, Japan has publicly demanded that the US commit itself to no-first use of nuclear weapons.

All these suggest that the new Japanese government doesn't want to follow the old path of "unequal alliance" with the US.

The two sides have marked differences on some other major specific issues, too, such as cooperation in the Indian Ocean, under which Japan provides energy support to US navy vessels involved in Afghanistan, and the relocation of the US military base.

These problems cannot be swept under the carpet during Obama's visit to Japan over the weekend. If the two countries could face up to the changing situation and try to adapt to each other's new positions, their relationship may enter a new phase that would help the peaceful development of the Asia-Pacific region.

But if Washington follows the path of Secretary of Defense Robert Gates, who recently professed to continue its "hard line position" toward Japan, Tokyo may make concessions under pressure but will not be satisfied with the relationship. This will rob US-Japan ties of its sincerity and trust.

Some public opinions suggest that Washington and Tokyo both are playing the "China card", that is, using their relationships with Beijing to "press" the other side to compromise. This may not sound unreasonable, but that is not the right way of maintaining relationships.

China hopes to develop sound relations with the US and Japan both, and wants to see US-Japan ties move toward a more mutually beneficial cooperation. As for the triangular relationship, China neither wants the continuation of "the US and Japan vs China" policy, nor does it intend to join hands with the US to counterbalance Japan. An equal triangular relationship based on mutually beneficial cooperation is what it is really pursuing.

The author is a Beijing-based researcher on international relations.