They invited U.N. Ambassador Donald McHenry, got instead National Security Adviser Zbigniew Brzezinski, who in turn sang the praises of former U.N. Ambassador Andrew Young.

It was the lastest roung last night what some observers see as an administration counter-offensive defending a foreign policy that has come under increasingly heavy fire in recent days.

For 950 guests at the third annual dinner to raise money for the Joint Center for Political Studies, it was also a rare glimpse of Brzezinski lecturing from the "chair" of Carter Diplomacy.

If the substance was international affairs the emphasis was on "geopoltical equilibrium in the context of world change," he said. Which was heavy stuff, to be sure, but exactly the kind that think tanks like the Joint Center are supposed to thrive on.

Since this one specifically thrives on needs and concerns of black minorities, there may have been a subemphasis on Third World countries, especially those in Africa.

Which is where Brzezinski's tribute to Andy Young got into the act.

"Thanks to the unflagging efforts of Secretary (Cyrus) Vance and particularly to the creative innovative spirit that Andy Young has used in our diplomacy," Brzezinski said, "we altered fundamentally our relations with Africa."

Not that the evening started out so seriously, mind you, Atlanta's Mayor Maynard Jackson, in introducing Brzezinski, told the story about the five men and four parachutes in a plane about to crash. The pilot needed the parachute in order to go back and sign all the papers, the general needed one for national security and the secretary of state, "the most brilliant person in the world," simply needed to be saved.

After all three had jumped it left the minister who told the student to go ahead and take the remaining 'chute. But the student reassured him there was one for each of them after all.

"The most brilliant man in the world grabbed my knapsack when he jumped," said the student.

"I've heard that joke before," Brzezinski told Jackson, who claimed he wasn't there to introduce the most brilliant man in the world. "But when I heard it," Brzezinski continued, "the most brilliant man in the world was Henry Kissinger."

Kissinger, in absentia, got his second lump of the evening when Brzezinski reminded everybody that four years earlier "our secretary of state" couldn't get into Nigeria for a visit.

The Carter administration, on the other hand, committed itself to majority rule in Africa, he pointed out, and the principle that problems there should be solved by African states.

On the Middle East Brzezinski drew mild applause when he said the objective, after effecting the Israeli-Egyptian peace treaty, has been "to achieve a comprehensive settlement which also yields dignity and fulfills the legitimate rights of the Palestinians as well.

"We believe this objective is good for Israel. And we therefore support strongly their autonomy plan that parliament is debating.We believe it is good for the United States and we believe this is the basis for seeking a cooperative relationship with the moderate militants that endures and is responsive to the aspirations of the increasingly assertive and influential Arab world."

"Whew," one listener said later.

At a VIP reception before the dinner at the Washington Hilton, the guests voiced quiet dismay about the choice of presidential candidates. Nobody seemed to be singling Carter out for any special abuse.

"It's like Coleman Young said," remarked LeRoy Jeffries, a marketing consultant from Los Angeles, "'Who the hell are you going to vote for?' Carter's economic message will hurt him with blacks but they have no place else to go."

Earl G. Graves, editor and publisher of Black Enterprise magazine and, with Rep. Parren J. Mitchell, (D-Md.) the evening's honored guest, worried about prospects for blacks in business. "The key problems facing minorities in business is still access to capital."

Washington's Mayor Marion Barry put his concern another way: "We've made a great deal of political progress, but looking around the country now we also need a piece of the economic pie."

Something Eddie N. Williams, center president, found ironic. "Just at the time when we thought we could make the greatest economic strides, minorities are going to be the hardest hit."