Call it the slap heard 'round the continent.

While Canadian Prime Minister Brian Mulroney and about 200 dinner guests waited inside the Canadian Embassy Wednesday night for the arrival of Vice President George Bush, Sondra Gotlieb, wife of Canadian Ambassador Allan Gotlieb, slapped her social secretary in the face, in full view of more than a dozen observers, including several members of the Canadian press corps. Social Secretary Connie Connor, who was announcing guests, ran out of the foyer and down the steps of the Rock Creek Park residence, one earring missing and her hand to her face.

She and Sondra Gotlieb reappeared soon after in the foyer, both of them smiling. Guests were unaware anything had happened. The party continued.

But the story got out yesterday, and when it did, the Canadian media responded with a frenzy of questions. As Washington telephones began to jangle, guests at the black-tie dinner expressed amazement and the social world closed ranks around the ambassador's wife.

Sondra Gotlieb, who writes a column for The Washington Post describing the vagaries and frustrations of diplomatic life in the form of letters home to a friend, was not available for comment, an embassy spokesman said. Embassy staffers said Connor, an American who previously worked in the State Department's protocol office and has been at the embassy for several years, had left for vacation.

The embassy's minister for public affairs, Bruce Phillips, released a statement: "I am informed that an incident of a purely personal character occurred last night before the embassy dinner. The incident was immediately regretted, an apology extended at once and at once accepted, and the issue was immediately resolved. There have been no resignations and no staff changes."sk

In diplomatic circles, where protocol is all, social gatherings are usually as sedate and well choreographed as a minuet. But Wednesday's party was not beginning as smoothly as a hostess might hope, some guests said.

One described the embassy staff as flustered because the vice president was late due to a political trip, and said Sondra Gotlieb was upset because Deputy Treasury Secretary Richard Darman, a prized guest, had not arrived either. Gotlieb reportedly asked Connor where Darman was. Connor said he was not coming. Gotlieb then asked why she hadn't been told that he had rescinded his acceptance. Connor insisted that she had informed Gotlieb, and the slap followed.

After dinner, a guest said, Allan Gotlieb made a point of going to Connor and congratulating her on the success of the evening. The Canadian Southam news service is reporting in stories today that Connor has been unhappy at the embassy and is looking for another job.

Yesterday, Sondra Gotlieb did not accompany her husband to the Mulroneys' departure ceremonies. In the afternoon, she attended a lunch at the home of socialite Buffy Cafritz. One guest said Gotlieb received a phone call there and looked visibly upset afterward. "We're all getting calls," the guest said. "We're to put up a wall to protect her."

That's a wall Canadian reporters seemed determined to breach yesterday.

"Would you describe this as a diplomatic incident?" one Canadian television reporter asked a U.S. reporter.

"For Canada, it's not a gossip story," said William Johnson, Washington bureau chief for the Toronto Globe and Mail. "This is considered a fairly significant story. It happened at a very public event, a very high profile event, with the prime minister in residence."

"The dinner party is a subject fraught with so many categories and ensuing anxieties that only a PhD thesis can do justice to it," Sondra Gotlieb wrote in an article titled "How to Run an Embassy."sk

Guests at the dinner described their evening as "lovely" and "relaxed" but admitted Gotlieb may have had a different experience.

"Can you think of anything worse than being 'wife of'?" said Rep. Patricia Schroeder (D-Colo.), one of the guests. "I think they're on the front lines and these kinds of visits must be enough to drive anybody mad. The poor prime minister was absolutely dead. Your whole back yard is torn up and there's a tent and the wind is blowing. I don't how how they tolerate that. It probably makes Christmas look like an easy season."

Mulroney was not actually dead, merely suffering from the flu. But several guests did cancel at the last minute. And for Gotlieb, who wrote in the April issue of Vanity Fair that "everyone in Washington wants to be in bed by eleven," the late arrival of the vice president presented another source of distress. Several guests agreed that Sondra Gotlieb looked harried, running upstairs at one point, to the clear concern of her husband.

"Last night was tough for Sondra," said guest Joan Braden. "She is wonderful at small things, but when it gets this big and they'd been out the night before . . . My hunch is she'd had one hell of a time."

Susan Mary Alsop, who had missed the party because of the flu, said "oh, dear" when she heard about the slap and that it had been witnessed by the some members of the press. "You mean that nice Connie Connor? She's the nicest girl in town. What happened to Mrs. Gotlieb? Sondra Gotlieb must have been very tired, is all I can say. I think it just means two women were just worn out by people like myself dropping out at the last minute.

"I think we just don't talk about it. She's such an important and marvelous friend. Nobody in Washington is going to fuss about it."