By Frank Ching

U.S. President Barack Obama's visit to Japan brought forth renewed utterances of support of their bilateral security treaty, but the new Democratic Party of Japan government of Prime Minister Yukio Hatoyama appears determined to make it a more equal alliance.

And, for his part, Obama appeared more than willing to accommodate Japan. In fact, he quoted President Dwight Eisenhower as saying 50 years ago when the alliance was first inaugurated that it was ``an indestructible partnership" based on ``equality and mutual understanding."

But everyone knows that over the last half century it was always the United States leading and Japan following.

A major reason was Tokyo's reliance on Washington for its security. Moreover, the economic relationship was extremely close, with the United States being Japan's biggest trading partner year in and year out.

But that is beginning to change. China's emergence, and that of East Asia generally, has changed the situation on the ground.

For two years now, China has replaced the United States as Japan's biggest trading partner. And the trend looks set to continue.

In the first six months of this year, China has become Japan's biggest trading partner in terms of both exports and imports, marking the first time that Japan's exports to China exceeded those to the United States.

Even though Japanese exports to China fell 25.3 percent from the same period last year, those to the United States showed an even larger decline, thus propelling China into first place.

Of course, trade alone does not determine a country's relationship with other countries. Britain, for example, ranks sixth in terms of American trading partners, but the United Kingdom has always enjoyed a special relationship with America for reasons of language, history and culture.

But the rise of East Asia as a whole means that Japan is now re-evaluating its future relationship with the United States.

During the election campaign, Hatoyama advocated the formation of an East Asian Community, without specifying which countries he had in mind for membership.

In Singapore last weekend, he indicated that the United States was a potential member of such a regional grouping.

However, this is a far cry from the situation almost two decades ago when the Malaysian leader Mahathir Mohamad proposed an East Asia Economic Caucus, grouping the states of the Association of Southeast Asian Nations (ASEAN) as well as China, Japan and South Korea but without the United States.

Japan refused to go along because of the exclusion of the United States.

Since then, however, Japan has become a member of the East Asia Summit, which groups ASEAN with the three Northeast Asian countries, plus India, Australia and New Zealand, without American participation.

President Obama suggested in his speech in Tokyo that the United States wants to engage ``with the East Asia Summit more formally," a possible indication of a desire for inclusion.

Moreover, Japan, China and South Korea are holding annual summit meetings to discuss economic cooperation. Japan is also talking with ASEAN about a free trade agreement and China, Japan and South Korea are jointly considering an FTA.

The economist Andy Xie wrote recently in Caijing magazine: ``Japan has a strong and genuine case that favors more integration with East Asia. The United States is unlikely to recover soon and with enough strength to feed Japan's export machine again. Without a new source of trade, Japan's economy is doomed. Closer integration with East Asia is the only way out."

Of course, economics and politics are separate but related. Marxists like to say that the economic base determines the superstructure, which may suggest that stronger Japan-China economic relations will shape their political relationship.

But political suspicions between Japan and China are a fact of life and given Japanese apprehension of China's intentions as it grows not only economically but also militarily, Tokyo is unlikely to want to weaken its security relationship with Washington.

Moreover, the United States under the Obama administration is keen to make up for lost time and bolster its influence in East Asia.

That being the case, the Japan-U.S. relationship is likely to remain strong for as long as China remains viewed as a potential threat by Japan and other countries in East Asia.

And the United States, which remains by far the most powerful player, needs to pay attention to its friends in this part of the world.

The current perceived decline in American influence is due in part to neglect of the region over the last decade, especially during the Asian financial crisis, when it was China that stepped up to provide assistance.

Frank Ching is a Hong Kong-based writer whose book, ``Ancestors: 900 Years in the Life of a Chinese Family," has just been reissued in paperback. He can be reached at Frank.ching@gmail.com.