Washington — While Washington plays friendly host to the world's finance ministers and central bankers, many of the guests mutter darkly about lack of United States leadership on the global debt problem.
To hear visiting bankers tell it, the danger of a world financial crisis will markedly increase if Congress fails to pass an $8.4 billion US contribution to the International Monetary Fund (IMF).
Many American experts agree. Without US participation in a planned 47 percent boost of IMF resources, says former Assistant Secretary of State Robert Hormats, the IMF ''would be almost crippled.''
The US contribution by itself will do little to shrink the developing world's enormous $700 billion debt burden, owed mainly to commercial banks.
But the IMF is a catalyst in two ways:
* When the 146-nation IMF lends money to a debtor land, it imposes ''conditionality'' - a requirement that the government getting the money set its economic house in order.
When private banks make loans to developing nations, they can make no such demands on sovereign governments.
* A loan from the IMF unlocks fresh credits from commercial banks, which are reluctant to lend more money to nations like Brazil and Mexico unless the IMF backs them up.
Unless Congress agrees to the $8.4 billion US contribution, other nations may renege on their pledges. Already the IMF is strapped for lendable cash.
''Pragmatic American interests overwhelmingly favor supplying the IMF with that money, both on grounds of US jobs and security,'' says Mr. Hormats, vice-president of Goldman, Sachs & Co.
''Three hundred thousand American jobs have been lost over the last 18 months ,'' says Hormats, ''because of import cutbacks in Latin America alone.''
Forced to use their available dollars to pay interest on their huge debts, Mexico, Brazil, Argentina, and other Latin American debtor lands have reduced their imports of US goods.
''Every exporter in this country,'' says Hormats, ''should be weighing in heavily in favor of the IMF quota increase. But they are not.''
Neither, he said, are US labor unions whose members work in export-oriented industries lobbying for the increase, although many American jobs depend on exports to developing lands.
''Four percent of the US GNP (gross national product) is exported to developing countries,'' says Hormats.
''If the IMF is jeopardized,'' said C. Fred Bergsten, a former high US Treasury official, ''the outcome in Brazil, where the situation is balanced on a delicate knife's edge, could be dangerous.''
Hundreds of thousands of Brazilian workers recently rioted in opposition to austerity measures decreed by the IMF as a condition of fresh loans. If they were deprived of IMF resources, Brazilian authorities also would be shorn of international backing for taking tough economic steps at home.
''Loss of IMF resources,'' said Mr. Hormats, ''would increase pressure on debtors to seek unilateral solutions.'' Simply put, that could mean repudiation of their debts, which in the case of Brazil amount to $90 billion - the largest in the world.
A default of this magnitude, especially if others followed suit, would pose a major challenge for some major American banks and plunge the international financial system into uncharted waters.
The bottleneck in the IMF debate is not the Reagan administration, which supports the $8.4 billion increase. President Reagan, addressing assembled finance ministers and central bankers Tuesday, stressed American backing for larger IMF quotas.
''If Congress does not approve our participation,'' said Mr. Reagan, ''the inevitable consequence would be a withdrawal by other industrialized countries from doing their share. At the end of this road could be a major disruption of the entire world trading and financial systems.''
But Congress, where sentiment is mixed, continues to bicker over the IMF legislation. Critics charge that US taxpayers are being forced to ante up to bail out US and other banks that made imprudent loans.
Experts agree that imprudent loans were made. But, they ask, which is worse: fresh loans to give debtors more time to boost exports and benefit from world economic recovery, or possible default and social turmoil on America's southern doorstep?
The IMF provides bridging loans to help debtors solve balance-of-payments problems. Beyond this, the World Bank - through the International Development Association (IDA) - grants long-term, no-interest loans to the world's poorest lands.
Here, the US as a whole, including the Reagan administration, is accused of lack of vision by many banking officials.
World Bank president A. W. Clausen, former head of the Bank of America, says IDA needs a $16 billion fund replenishment from member nations over the next three years. The US insists that $9 billion is enough.