Boycotting the 1980 Olympic Games in Moscow next summer and stopping wheat sales, commercial credits and cultural exchanges to the Soviet Union were among a wide range of retaliatory moves discussed by the NATO allies today in response to the Soviet invasion of Afghanistan.

No decisions were made at the grim, New Year's Day emergency meeting of NATO ambassadors with U.s. dEputy Secretary of State Warren Christopher at NATO headquarters here. But informed sources said there was a clear consensus that whatever actions are taken after further consultations must be firm and convincing.

"Whatever is done after consultations must be credible," the representative of one major NATO country said here today, according to informed sources. "We dare not take actions we cannot really deliver on, because our credibility will suffer." t

Another NATO ambassador reportedly said, "I hope we do not yield to appeasement."

Following Christopher's more detailed preliminary meeting in London yesterday with ranking diplomats of Britain, France, West Germany, Italy and Canada, those nations have begun soliciting the support of Third World countries for United Nations condemnation of the Soviet invasion. Britain and several of the others also have instructed their ambassadors in the Afghan capital of Kabul to avoid political contacts with the new Soviet-backed government there.

Stronger diplomatic action against Afghanistan and the Soviet Union is now to be coordinated by the NATO allies. An earlier emergency meeting on the Afghan crisis was held by the NATO council last Saturday.

Another NATO ambasador reportedly compared the scheduled 1980 summer Olympic Games in Moscow with the 1936 Olympics in Adolf Hitler's Berlin. "If we go to Moscow," he asked, according to sources, "is that not an expression of busines as usual? Are we going to continue business as usual?"

Boycotting the Olympics, stopping grain sales to the Soviet Union, or cutting off its Western commercial trading credits all were raised both at NATO meetings here and at yesterday's consultations in London, according to sources. The SALT II nuclear disarmament treaty, signed by both the United States and the Soviets but not yet ratified by the U.S. Senate, also was discussed.

Some NATO officials, according to sources, suggested that the Carter administration abandon its stated detente policy of avoiding linkage between these relationships with the Soviet Union and that country's actions elsewhere.

Christopher told the others that the Carter administration is committed to continuing to seek Senate ratification of the SALT treaty, but that its chances would undoubtedly be affected by this past weekend's events in Afghanstan.

One source said the meetings of the allies have produced "a strong sense of solidarity and a feeling that this is a matter of extremem seriousness. There is no sense of seeking to be careful." This appeared to be a significant shift in mood from the perceived hesitancy in some European capitals after the U.S. hostages were taken in Iran.

After today's meeting, NATO Secretary General Joseph Luns said in a statement to reporters that "the armed Soviet aggression in Afghanistan is a flgrant violation of international law and a threat to peace. This is the first time that the Soviet Union has used its military power directly and massively in a country not belonging to the Soviet Bloc. More than ever, solidarity and decision among the allies are imperative."

Before flying back to Washington, Christopher said that he told the allies the "massive land invasion" of Afghanistan had put 30,000 to 40,000 Soviets troops inside the rugged country on its southern border. He said all 15 NATO nations sheared with the United States "a deep concern about this strong agression."

NATO sources said it did not appear that the Soviets were threatening to move beyond Afghanistan. There was no mobilization of Soviet troops elsewhere, they said, and it appeared that those inside Afghanistan would concentrate on helping subdue resisting units of the Afghan Army and rebellious Moslem tribesmen in western regions near the borders with Iran and Pakistan.

There was relatively little discussion of Iran or Pakistan at today's meeting here, according to NATO sources.