The state dinner was done, the toasts concluded, and there, over in a corner of the Green Room, you could find national security adviser Richard Allen deep in conversation with the guest of honor, West German Chancellor Helmut Schmidt. They spoke in German.

Secretary of State Alexander Haig, a man who isn't known for his close friendship with Allen, was standing a sword's length away. How can you let Allen monopolize Schmidt? he was asked.

"He has to," the secretary of state replied. "He has to apologize."

For what?

"For being Dick Allen," Haig deadpanned.

Here's what Allen said: "As for me apologizing -- come, now."

And so it went at the dinner given by President Ronald Reagan for Helmut Schmidt at the White House last night, a dinner that stressed warm ties between the two nations. "We agree with the German poet Henrich Heine, who wrote, 'Germany will ever stand -- It is a hail and hearty land,'" Reagan said in his toast to Schmidt.

Schmidt responded: "We hope that your administration will soon meet with success in its efforts to overcome economic difficulty . . . our American friends can rely on us just as we do rely on the United States."

Schmidt's toast was a long one. "We are still feeling the shock at the attempt that was made on your life," he said to Reagan. "I cannot tell you how much I was relieved this morning seeing you getting out of the car and standing upright."

It was the end of an important day for the two leaders, a day when they talked for 70 minutes about Soviet arms negotiations and American interest rates. Substance done, the evening was for play -- also for underscoring, as you can with carefully worded toasts and good wine, that American-German relations are expected to improve from the chill left on Schmidt by the Carter presidency.

But Schmnidt was the polite guest, and so didn't publicly compare the two administrations. "That's a question I would rather not answer," he replied to an after-dinner query asking if he hoped for better relations now that Reagan is president. "I have certainty for very good relations. I won't critize President Carter."

"Not much," came a muttered aside from an eavesdropping White House official.

Schmidt and his wife, hannelore, arrived at the White House just after 7:30 p.m. The sun was still out, filtering through the trees and glancing off the glinting metal of the guns held in salute by the military guards. Reagan and his wife slipped onto the North Portico to greet their guests, acting like the expectant hose and hostess they were. Reagan fidgeted a little, then made quiet small talk with his wife. She smiled nervously, the sun this time catching her dangling earrings that went with a one-shoulder white Adolfo dress.

When the Schmidts pulled up in their limousine, everyone shook hands, exchanged pleasantries and posed for pictures. Schmidt stood with one hand in a pocket, looking around at the scenery. The other three stood obediently. i

Downstairs, through the South Portico entrance, you could get a look at the other guests. A small ensemble played "The Blue Danube Waltz." Through the entranceway you could see the White House fountain, the Jefferson Memorial and people playing softball on the Ellipse. It was a fine night to be in Washinton.

Former Federal Reserve Board chairman Arthur Burns, the new ambassador-designate to West Germany, certainly thought so. "It's a privilege I'm not going to deny myself," he said grandly of his selection.

And what does he know of Germany?

"Well," he said, pausing thoughtfully and furrowing his trademark white eyebrows, "I even know German literature."

As is normal, many of the other guests had praise for Burns.

"Our relations with Germany deserve such a man," said U.N. Ambassador Jeane Kirkpatrick.

"He has statesmanship, brilliance and knowledge of European politics," said William Clark, deputy secretary of state.

The guest list itself was more diplomatic and less Hollywood, balanced between amabassadors, former ambassadors, congressmen and senior White House staff.

But also included were designer Bill Blass, actress Claudett Colbert, Commentary magazine editor Norman Podhoretz, actor Efrem Zimbalist Jr., ABC anchor Frank Reynolds, and Vernon Jordan, executive director of the National Urban League. He's on record against Reagan's cuts in welfare programs.

"I'm not going to talk about that tonight," he said, fresh from the dance floor. "I'm in opposition to his program, yeah. But that has nothing to do with my presence here tonight. The president and I have a very special bond. I went to see him in the hospital." Jordan, like Reagan, also survived an assassination attempt.

After a dinner of smoked filet of mountain trout, roast supreme of duckling a l'Orange and fresh raspberries in the State Dinning Room, the crowd of 96 listened to the Juilliard String Quartet in the East Room. There were geraniums arranged around a small stage, small white lights on the indoor trees, and a tired group of White House staffere collapsed onto chairs in the nearby Green Room. When the formal entertainment was over, the party turned to the marble dance floor in the Great Hall.

Not everybody danced, but the president and first lady did. Slowly. They said hello to guests, and Nancy Reagan even kissed Frank Reynolds on the cheek.

"I didn't mind," said Reynolds.

"Oh, she kissed him many times," said Reynolds' wife, Henrietta.

The Schmidts left first, and were followed into the pleasant spring night by Vice President George Bush and his wife, Barbara.

"Nice party," said Barbara Bush to Nancy Reagan.

The couples waved goodbye.

"Good night, George," Nancy Reagan called to Bush.

"Good night, sir," Bush called to the president.