When President George W. Bush of the United States lands in Santiago, Chile, for the 12th annual summit of the Asia-Pacific Economic Cooperation (APEC) in a few days, he will certainly be congratulated on his re-election.

But the 20 other APEC leaders -- including Prime Minister Lee Hsien Loong of Singapore -- aren't showing up in Santiago merely to backslap with Bush.

They will expect him to be specific about the financing of the growing U.S. deficit, estimated to exceed $600 billion this year.

The Asian leaders, especially, are certain to raise the question of their continued, low-interest lending to the world's most powerful economy -- lending that's likely to make the global economy even more imbalanced in the months ahead if a slowing U.S. economy results in higher deficits.

"Extricating the United States from its dependence on Asian financing to make up for a lack of domestic American demand, and Asia from its dependence on an already too-indebted American consumer will be an extremely difficult challenge," says Professor Brad Setser of the Global Economic Governance Program at University College, Oxford.

The other issues that may make Bush's Santiago sojourn somewhat less than relaxing concern the falling U.S. dollar and whether China -- whose economic growth is again showing signs of resurgence -- is inevitably headed for a hard landing.

The continued weakening of the U.S. dollar -- against market- driving currencies such as the Singapore dollar -- particularly worries Asians because a depreciating U.S. dollar makes their own exports more expensive.

And, says Andreas Carral, Mexico's ambassador to Singapore, some APEC members are already worrying that the traditionally economic forum may be pushed by Bush into taking a stronger political stance on issues such as counter-terrorism.

The convergence of the economic issues will affect Bush's political agenda for his second term: Winning the costly war in Iraq, partially privatizing social security and not raising taxes but spending more on defense and on combating terrorism.

To carry out his agenda, President Bush needs to borrow large sums -- as cheaply as possible -- and only Asian central banks have been lending to the United States on Bush's optimistic terms.

Professor Setser, the former acting director of the U.S. Treasury's Office of International Monetary and Financial Policy, says, "Bush wants the current pattern of Asia lending to the United States and financing both U.S. budget deficits and the purchases of Asian goods to continue."

That's worrying for APEC leaders, because the $11 trillion American economy remains the world's most powerful engine for economic growth. Any slowdown will affect everybody else.

APEC's membership makes it arguably the world's most powerful grouping of nations, accounting for nearly three billion people, or almost half of the global population of 6.2 billion; a combined gross domestic product of $20 trillion or more than half of the world's GDP; and 47 percent of world trade, which was $10 trillion last year, and is expected to grow by 8.5 percent this year.

Typically, fiscal deficits are financed through foreign borrowing. Last year, according to the Bank of International Settlements, global reserves increased by $500 billion, and Japan and emerging Asia -- including India -- accounted for $465 billion of this increase ($200 billion from Japan, $265 billion from emerging Asia). Of that, $441 billion was invested in dollar assets.

The New York Federal Reserve Bank -- the biggest of the U.S. Fed's 12 regional banks -- believes that this $441 billion is a better estimate of central bank financing of the U.S. current account -- better known as the trade deficit -- and the budget deficit -- the difference between what the government spends and what it earns through taxes and levies -- than the more optimistic data published recently by the U.S. Department of Commerce.

If that was the case, foreign central bank reserves provided about 80 percent of the financing needed for the U.S. current account deficit last year -- and most of that was from Asia.

In the first half of this year, Japan added $145 billion to its reserves, and emerging Asia added $125 billion. If that trend is sustained through next month, Japan and emerging Asia would have provided a comparable amount of financing for the U.S. current account deficit this year.

However, while emerging Asia is continuing to add to its dollar reserves, Japan has stopped. If Japan continues to stay out of the dollar-currency market, that would imply Asian reserves accumulation this year of $400 billion -- $250 billion from emerging Asia, roughly $150 billion from Japan.

Economists aver that if Asia ever stops building up its reserves at its current pace, or stops investing those reserves in the greenback, the U.S. would be in for an unpleasant shock.

Much higher interest rates would be needed to attract private flows of a comparable size, and those high interest rates would slow the U.S. economy.

Without financing from Asian central banks, the U.S. economy most certainly would have to contract, reducing the size of the current account deficit and the amount it needs to borrow. But ironically it would still pay more to attract financing to cover what would still be a large current account deficit.

A $600 billion current account deficit this year is not small by any means, but it would still be much smaller than the $700 billion deficit likely next year if nothing changes.

President Bush will certainly be reminded by Asian leaders in Santiago that while ending current U.S. dependence on Asian central banks would be extremely costly if it happened suddenly, it also is not a long-term positive for the global or the U.S. economies, said Manu Bhaskaran of the Centennial Group.

But the U.S. external debt is no longer small -- it will be close to 30 percent of GDP at the end of next month.

That's why economists worry that U.S. demand for external financing may outstrip Asia's supply of financing -- whether because of growing U.S. demand, or reduced Asian supply, or both.

When that happens, it will leave the global economy even more out of kilter.

But while Bush's Santiago stay will be more somber than the usually ebullient Texan would like, the host country is unlikely to allow U.S. concerns to affect the festivities. Insatiable appetite for its copper from fellow APEC members like China has given Chile much to cheer about through trade surpluses.

So when the APEC Class of 2004 picture is taken, Chile's President Ricardo Lagos Escobar will be the man wearing the biggest smile. No deficits for him.