The thin cream-colored notices arrived last week.

The embassy of Qatar -- representing the tiny Arab gulf state -- which isn't exactly on the front lines of Washington's night life, canceled its national day celebration this week due to the fighting in the Mideast. A few days later, the Saudi Embassy also announced plans to cancel its national day celebration here next month.

Qatar Ambassador Abdelkader Ameri said this week that the decision to cancel national day festivities, comparable to our Fourth of July, came from the ministry back home.

The formal announcement explained that the event was being called off "due to the Israeli invasion of Lebanon and their acts of genocide against the Lebanese and Palestine people . . ."

"All the Arab states in the gulf decided together not to celebrate any holidays in the next few months," said Ameri, who described his country as "very small and very rich."

"We can't have dancing in the streets when people are being killed. This war has left hehind more that 15,000 wounded . . . I doubt if there will be any Arab celebrations this month . . ."

Last spring it was the Falklands crisis that caused former British ambassador and social darling Sir Nicholas "Nico" Henderson to decline invitations to parties all over town. Inside Washington was privately chagrined. He didn't even make the book party of his good friend Henry Kissinger at the home of another good friend, Joan Braden.

"My country is at war," he said, as he declined tennis and dinner invitations.

And as the fall season gets under way, it looked as though the Mideast war might cause the socially desirable Saudi Arabian Ambassador Faisal Alhegelan and his glamorous wife, Nuoha, to withdraw. A few weeks ago, Mrs. Alhegelan, who led a media blitz for the Arab Womens Council this summer to "humanize the war," said she will not contribute to Washington charities this year.

Instead, the Alhegelans say they will give their money to the Arab world. And that could mean a lot of $250 ball tickets, as the wealthy Arab embassies are a dependable source of charity and arts revenues around town.

But that's as far as their autumn social withdrawal will go, Mrs. Alhegelan says. The couple will go out this month.

"Life has to, of course, go on," Mrs. Alhegelan said. "We have certain obligations here and a job to do and we will do it. We have to pick up and start our lives again without losing sight of what has happened in Lebanon."

"It's too soon to tell what we'll do," said a spokesman at the Oman Embassy, which has planned its national day celebration for November.

Spokesman at the embassies of Jordan, Lebanon, Kuwait and Morocco said there were no plans to cancel any events, and ambassadors will be as visible around town as ever, buying tickets and all.

The Israeli Embassy reports business as usual, too.

"We're still working very hard and we are doing our best to just keep going on," said Israeli press attache' Nachman Shai. "The ambassador is in Israel now, and when he comes back everything will be the same. We have nothing big like a national day planned, but there are no plans to cancel anything.

"You can be sure you would not see any parties or celebrations in Israel these days either, but you have to figure that Qatar and countries like this have a very different perspective on the war . . ."