Yelena Bonner, who is a forthright and demanding woman, wanted a birthday party for her husband, and she got one.

It wouldn't be everyone's idea of a gala, although there was a cake and champagne of sorts. The speeches were long, and of course, the newly 65-year-old guest of honor, Andrei Sakharov, was absent. Bonner, nonetheless, seemed elated.

Decked out in white silk and garnets, she was with her 85-year-old mother, a fragile figure with tightly drawn skin who looks like a character from a 19th-century Russian novel. Her daughter and son -- children of a previous marriage -- spelled each other as her interpreters, and she greeted warmly the score or more of politicians who joined the turnout in the House Foreign Affairs Committee hearing room.

Bonner was a nurse in World War II and is obviously accustomed to emergencies. She has been in one since 1973, when the Soviets cracked down on her and her husband for declaring openly that Russians have a right to human rights, as guaranteed in the Helsinki Accords.

For a while, Sakharov's fame saved him from the worst consequences of his heresy. He is a Nobel laureate, father of the Soviet H-bomb and demonstrably one of the world's preeminent scientists. When the authorities were about to strike, Bonner was on the telephone, at all hours, to Western correspondents, advising them of new torments in store, often averting them.

But in 1980, when the Soviets invaded Afghanistan and Sakharov denounced the action, their chancy, although exhilarating, existence was ended. The Sakharovs were exiled to the wretched hamlet of Gorki. They were cut off from friends, family and fellow scientists.

After Sakharov staged a hunger strike, the Soviets reluctantly let Bonner come to this country for heart surgery. She was supposed to lower her voice while here. She did not. Once a chain smoker, she gave up cigarettes. But she hasn't given up free speech.

Obviously, it costs the Soviets to treat so shamefully a man designated three times a "hero of the Soviet Republic" and a person of qualities that make him nothing less than noble. But they bear the universal disgust that greets each attempt to rationalize the persecution rather than risk the informed jeremiads of a freed Sakharov.

Sakharov is no Solzhenitsyn, who turned out to be a Slavic born-again with ideas fresh from the Middle Ages. After the initial furor of his release, Solzhenitsyn disappeared from public consciousness. Sakharov is a modern man, questing, progressive, focused on the imperatives of the nuclear age.

His wife, after six months, must go back to join him in exile. At the birthday party, this intrepid soul said that she is "dreadfully afraid" of what awaits her.

She wants protection, which to her is public tributes and expressions of concern for her husband. Protection means Western scrutiny as unrelenting as KGB surveillance. Congress wants to oblige. Rep. Jack Kemp (R-N.Y.) gave her a bill that would award both Sakharovs the Congressional Gold Medal.

In her presence, the term "quiet diplomacy" slinks away. Clamor, to her, is the only way. Anatoly Shcharansky, another recent Soviet visitor, got out after nine years because his wife, Avital, never stopped reminding the world of his unjust imprisonment.

Shcharansky said last week that ". . . no quiet diplomacy without strong public pressure can help."

Bonner, expected, as did everyone else, that President Reagan, who has never practiced quiet diplomacy with the Soviets, would receive her with open arms. Bafflingly, his door is closed to her. Our vehemently anticommunist president has been strangely hooded in his treatment of these two fabled Soviet dissenters. He vetoed press cameras at his meeting with Shcharansky and a White House press briefing with the ebullient little survivor.

Bonner is not welcome at all.

Richard Pipes, a birthday party speaker and former Reagan National Security Council aide, blames Richard Nixon. "He tells Reagan that quiet diplomacy worked for 300,000 Soviet Jews, but it was the Jackson-Vanik amendment. The president looks both aggressive and indecisive this way, gets the worst of both worlds."

Reagan couldn't stay completely out of it, and on Monday sent Bonner what she called a "warm letter" and to the birthday party an Andrei Sakharov Day proclamation.

Bonner was asked if a meeting with Reagan would help. "Of course," she said. "You can't be for human rights and be secretive. We are not thieves in the night. We do not come with bombs and guns."