The ambassador of Qatar gave a farwell party for the ambassador of the United Arab Emirates last night and it was almost like back-to-school night on Embassy Row.

The Persian Gulf oil crowd was there along with other diplomats from the Middle East. And the social-circuit regulars were back on the track, some telling how they had jetted in from places like the Greek islands or the Hawaiian Islands or Nantucket Island or the island of Bermuda or even San Clemente which, technically, is not an island.

The wife of the Swedish ambassador, Countess Ulla Wachtmeister, said they had been away two whole months -- "much too long." Even so they had kept up with what was going on in Washington. And while quite a bit had gone on, bringing with it a lot of new faces, she had no intention of revising her embassy guest lists.

"I keep my old friends," she said. "I just add a few new names."

Quatar's Ambassador Abdullah Saleh Mana, who pronounces it "catarrh" and not "guiter" as the State Department advises, said he did not know how many people he invited since he was off in Bermuda meeting his foreign minister who was en route to Havana.

"I just gave them the list and said "here, do what you want with it," said Mana.

What they did with it was invite about 150 friends of Ambassador and Mrs. Hamad Abdul Rahman Madfa, a collection of people that included author Victor Lasky; former senators J. William Fulbright and Vance Hartke; Rep. Sonny Montgomery (D-Miss.); Dr. Muhammed Abdull-Rauf; director of the Islamic Center here; William Baroody of the American Enterprise Institute; columnist Joseph Kraft; Peter Krogh, dean of the Georgetown School of Foreign Service; and Hatem Hussaini of the Palestine Information Office.

Hussaini said he was unimpressed by reports that Israeli Foreign Minister Moshe Dayan had met recently with Palestinian supporters.

"Merely cosmetics," said Hussaini. "Dyan is playing a game. It doesn't indicate any change in Israeli policy."

More optimistic was Victor Lasky.

"Look," he said, "I was in Israel when the Egyptians were the enemy.The Israelis come to terms with the Palestinians."

Lasky said he had turned down Richard Nixon's invitation to John Mitchell's birthday party at San Clemente over the weekend (United Arab Emirates social secretary Susan Hurley, who once worked for Nixon at the White House, accepted it.)

"I called John whom I haven't seen since he got out of the slam and I called President Nixon to tell him I couldn't make it. I just got back from the coast and I'm not one of those guys who has a private jet waiting at the door, you know."

But already the word was circulating about how Nixon had sized up the Middle Eastern situation.

"The difference between the Americans and the Russians is that the Americans want peace in the Middle East," Nixon was reported to have told his guests, "and the Russians want a piece of the Middle East."