Apr. 11--Japan, China and the United States -- the world's three largest economies -- all face long-term challenges even after they successfully emerge from the current global crisis, Chinese and Japanese scholars told a recent symposium in Tokyo.

The three countries need to step up cooperation to ensure post-crisis global economic and financial stability, but they still face hurdles such as lingering mutual distrust and conflicting interests, they said.

The experts were taking part in the March 30 symposium organized by the Keizai Koho Center to discuss "new Japan-U.S.-China relations after the global financial crisis." Yasuhiro Goto, editor of the Asia and Oceania news department of the Nikkei business daily, served as moderator.

Behind the ongoing global recession is the increasingly close interdependency of the world's major economies, said Jin Du, a professor of international studies at Takushoku University. "If those economies had not been interdependent, they would not have been simultaneously hit by recession," Jin said.

Initial optimism -- backed by the so-called decoupling theory -- that Asia would be spared the most serious impacts of the U.S.-originated financial crisis soon gave way to the realization that no economies are immune to disruptions taking place in other countries, he said.

The export sectors of Japan and China have been hit the hardest. The origin of this problem, Jin said, is that the U.S. growth pattern based on debt-financed excess consumption is no longer sustainable, and the flip side is that the export-dependent growth of Japan and China cannot go on much longer.

The U.S. has been a major pillar of global demand, but its robust consumption has been supported by debts to countries like China and Japan, he said. "When this pattern collapsed, the U.S. economy was hurt, but so were Japan and China," he added.

Zhou Yong Sheng, a professor at China Foreign Affairs University's Institute of International Relations, said the three countries are "in a relationship of mutual dependency whereby they share both successes and failures."

Such a relationship is evident from hard data, Zhou said. Last year, China replaced Japan as the world's largest holder of U.S. government debts, accounting for about 30 percent of the outstanding U.S. Treasury bonds as of the end of December, he said.

Each of the three countries face near-term and longer-term challenges, Jin said.