At about the time that Secretary of State Alexander Haig was streaking off into the eastern sky from Andrews Air Force Base Wednesday night, bound for Peking, the Chinese embassy played host here for the Fans of the American Film Institute.

The night began at the AFI, with the screening of "Small Dagger Society," a 90-minute film -- no English, no subtitles, but lots of action -- billed as a "dance drama" in which ". . . the people of Shanghai County rose and fought valiantly against the rulers of the Ching Dynasty . . . and their imperialist masters."

The imperialist masters (Western merchants, circa 1853) were portrayed by Chinese dancers in white pancake and huge fake noses. Carrying whips and grinning malevolently, they abused Chinese laborers and in general disported themselves like capitalists run amok. And of course, they paid in the end.

The screening and a buffet supper at the Chinese embassy were to benefit the AFI. The Fans of the AFI president Ina Ginsburg masterminded the whole thing, and presided over the party afterward in a large banquet room decorated with a massive needlepoint tapestry of Chairman Mao and cheerful revolutionaries. The Chinese diplomats urged guests to the table, and steadfastly avoided talk about Haig's Peking visit.

"I think you should talk to Mr. Yu about that," said Mr. Shu Zhang.

"I think you should talk to Mr. Shu Zhang," said Mr. Yu. And so on.

"It will be a very good trip," said Lin Zhaonan, embassy minister and second in command while the ambassador is in China for the Haig trip.

The long table, lined with plates of food and piles of chopsticks, attracted a platoon of eager eaters, including Rep. Sidney Yates, Sen. Charles Mathias and author Herman Wouk, whose novel "The Winds of War" has just been translated and published in China.

"Fascinating how they portrayed westerners," said Sen. Charles Mathias, his eyes streaming from the spicy food he'd just eaten. "But that film was made in 1961. I'm sure perceptions have changed by now."

Either that or Alexander Haig is in more trouble than he thinks. The Newest Legionnaire

Into the yellow salon at the French embassy Tuesday noon stepped a woman, bearing aloft a wine-colored velvet pillow. Nestled on the pillow was a white cross wreathed in laurel, hanging on a necklace of red silk.

As champagne corks popped discreetly in the background, French ambassador Francois de Laboulaye tied the medal neatly around a military man's neck, and bestowed two near kisses on each cheek.

With that the glorious deed was done and U.S. Army Chief of Staff Gen. Edward C. Meyer had become a commander of the French Legion of Honor, and thus a lifelong ally of France who served there during the war and on two later tours of duty.

A proclamation from Paris was read: "General Meyer knows France well," intoned the ambassador. "He is held in high esteem by the allied forces. He developed the concept of interoperability of allied forces."

The Legion of Honor was created by Napoleon, and while there are many called to the lower ranks of chevaliers and officers of the Legion, few are chosen to be commanders.

"I am very honored to accept this award on the 200th anniversary of the Battle of Yorktown," said Meyer, and mentioned how fortunate it was for America to have had the two great French generals, Lafayette and Rochambeau, fighting on our side during the birth of the nation.

"Oh yes, Lafayette," the ambassador said later. "A very good public relations man."

The Israeli raid on Iraq's nuclear reactor and the death of a French technician, was brought up after the awards.

"The Israelis thought no one would be there [in the reactor area] thinking Sunday was the holiday [in Iraq]," said de Laboulaye. "But Sunday is not the holiday. Friday is the holiday.

"When your neighbor is doing something you don't like and you send nine Phantoms! Well, that is not a society."

With that, it was time for lunch, and presumably more toasts (Chateau Grand Something or Other, '76) to the glory of France and Franco-American amity. Lafayette would have been so pleased. Pictures of Propriety

Though all that was visible from Massachusetts Avenue were the purple ends of two Ridgewell's trucks, deep within the rose garden of the British embassy last Sunday, the well-connected of Washington donned ruffles and pinstripes in the name of Queen Victoria, and for the economic health of the Folger Library.

"Go and admire Dick's white buckskin shoes," Cynthia Helms told a group of friends. "It's the first time in 40 years they've been worn. That's really why we're here."

And sure enough, over in another little patch of the British embassy garden, walked former CIA director and ambassador Richard Helms. He approached a knot of pinafore'd folk and pointed his finger down to the tops of his gleaming buckskins, as yet unsullied.

The shoes were duly admired, and Helms continued his walk. "Dick!" said Gen. Thomas Musgrave. He didn't wait to admire the shoes. "You know what I say?" Musgrave announced. "He doesn't fool me. He looks like a CIA agent."

The program invited guests to partake of Devonshire cream and strawberries, "the memories of late Victorian England, the spirit, the hope, the joy recaptured . . ."

As the sun set on the British embassy, White House mover Michael Deaver and White House shaker Peter McCoy, representatives of a more modern empire, met on the lawn. Deaver wore navy and pinstripes and fit the occasion. McCoy, in pastel plaid trousers, cream-colored jacket, pink shirt and burgundy tie, did not.

"Great God on the mountain, Peter!" said Deaver."You look like an Easter egg!"

"I couldn't find anything else," McCoy mumbled. And then he blushed. The Party That Plays Together

Maybe God has decided that the Democrats have had enough troubles. The weatherman had predicted rain and thunder for the day Pamela Harriman had chosen for a fundraiser last week.

There was nothing of the sort. Instead, 400 or so young and affluent Democrats came out to support "Democrats for the '80s," Harriman's political action group. They chatted at poolside and grazed at the buffet table. Jazzman Charlie Byrd played for free, as Sen. Chris Dodd, former Carterite Stu Eizenstat, lawyer J. D. Wiliams and others plotted resurrection.

The breeze ruffled the ivy, the drinks were cool, the benefit coffers were full and in general it was easy to forget that the Democrats are down and out. So the Harrimans reminded them, but refused to despair.

"I know what it is to be a Republican," said Averell Harriman. "And I feel very sorry for them. I want to say that I've had a hell of a lot more fun since I've been a Democrat."