Diplomats and officials at UNESCO are unsure what to do to persuade the Reagan administration to change its mind about pulling the United States out of the organization at the end of 1984.
At time of writing the UNESCO Secretariat had made no comment on the American decision and was refusing to speculate on how the US withdrawal - it now contributes 25 percent of the organization's budget - would affect UNESCO programs after 1984.
But UNESCO officials point out the organization faced a similar financial crisis in 1974 when President Gerald Ford withheld the US contribution for two years after UNESCO voted to withhold funds from Israel and exclude it from its European group.
At that time Amadou Mahtar M'Bow, the director general of UNESCO, borrowed money from the Organization of Petroleum Exporting Countries to fill the gap. This time he says he will seek to borrow from international money markets to compensate for the US contribution.
But longtime observers of UNESCO here predict the US absence from the organization would effect much more than its budget. The US is one of the major world centers in communications, scientific research, and social sciences. Its absence would represent a serious cultural and intellectual blow to the organization.
The US move is seen here as intended to effect urgent changes in the management of UNESCO and prompt other members to take a closer look at the organization. West Germany said it agrees there is an urgent need for reform, but it has decided to stay in the organization to work to bring about changes. Britain is conducting a thorough review of UNESCO on the ministerial level.
Some UNESCO officials suggest the organization has two main options. If it decides, in reaction to the US move, to dig in and become more radical, it risks losing even more Western support. Western countries together furnish at least 69 percent of the UNESCO budget.
Alternatively, the secretariat and other member states may adopt a more conciliatory approach to US grievances and tone down the organization's radicalism.
Mr. M'Bow has become a central figure in the current controversy because of his management practices. Observers speculate his resignation could serve as the necessary ''countershock'' which might bring the US back.
The French are concerned that the US move could spark more withdrawals from the UN system. They anticipate a year of contacts and negotiations to try to persuade the Americans to stay.