Last Tuesday night at the Korean Woolae Oak Restaurant in Crystal City, Kim Dae Jung sat smiling while the guests, led by Mary Travers sang the anti-war song, "Blowing in the Wind" under crepe-paper garlands. Kim's face wore an expression of seraphic happiness, which was not entirely justified.

The next day he started the long flight home to Korea. He was accomapnied by an unarmed escort of 20 prominent Americans, who hoped to prevent the Korean government from trying, one more time, to kill him for his ceaseless efforts to bring democracy to his native land.

Kim, a man of great dignity and humility, made a short, moving farewell speech.

"I don't know if I can maintain my life," he said of his return. "I will not be in the prison immediately after my return. There is still the possibility of house arrest."

When he announced that he was going back after two years of self-imposed exile, the Korean Ambassador to the U.S. promptly declared that Kim would be arrested upon arrival and returned to prison to serve out the remainder of a 20-year term imposed on him in 1980. His death sentence was commuted on the intervention of Ronald Reagan.

The State Department was no more enthustiastic about the homegoing than the Korean government. Officials told Kim they could not guarantee his safety, and tried to persuade him to postpone his return until after the Korean elections, which are scheduled for next week. But Kim declined to change his plans.

Finally, our government extracted from Seoul a promise that Kim, a onetime, almost successful candidate for president, would be safe at least until after the Washington visit of South Korean President Chun Doo Hwan in April.

It was not much. It was not as much as it could have been. The Koreans set great store by the visit, and even without it, given their dependency on our good will and arms, would have done much more. But it was more than the Administration wanted to do and more than it has done before. They have been instructed in the limits of "quiet diplomacy" by the murder of another Asian democratic dissident, Benigno Aqino, who was shot upon arrival in Manila. Another assassination engineered by a thuggish client was more than they could face.

Kim's escort -- Rep. Edward Markey, D. Mass. called it "his security blanket" -- includes two congressmen, Edward Feighan of Ohio and Robert Foglietta of Pennsylvania; Patt Derian, who was in charge of Jimmy Carter's human rights program; Robert White, former U.S. ambassador to El Salvador; and Mary Travers. Foglietta's presence in the delegation is particularly irksome to the security-minded Koreans. He is a ranking member of the House Armed Services Committee.

Kim may be a marked man when his escort leaves him. But with all the fuss that has been kicked up and the extensive coverage on Asian television, the Administration is committed to his safety. And it has shown that although Reagan has all but foresworn human rights as a foreign policy goal -- anti-terrorism comes first and anti-communism matters most -- it can be moved. If enough attention is paid in Congress and in the press, action comes. And it seems to be learning, the hard way, the limits of "quiet diplomacy", its preferred method for coping with odious dictators.

"Quiet diplomacy" means that everyone is supposed to shut up while U.S. diplomats whisper into the ears of the oppressors that they really shouldn't jail, shoot, kidnap and torture people who express a preference for another form of government. Inch by inch, on human rights, the Reagan Administration is backing into positions they scorned when Jimmy Carter took them.

Last week the Reagan Administration took another step ,which was quite astonishing. In the Inter-American Development Bank, we abstained from voting for a $130 million loan for Chile. The reason: General Agosto Pinochet has failed to lift the state of siege. Last November in the same forum, we voted for two loans for Chile.

Since then, the usual congressmen called for a ban on all aid. The usual statistics came from Chile: 8,000 citizens temporarily detained, 600 subjected, without charges, to "internal exile." As usual, Pinochet claimed to be fighting Communists. Only the Reagan response was different.

Again, the Administration could have done more, could have voted against the loan -- which Chile got anyway. But when you consider that in December, in the UN, the U.S. declined to vote to condemn Chile -- and satisfied conscience with a press release deploring repression -- you can claim progress. Some think the action reflects the departure of Jeane Kirkpatrick, the Administration's cheerleader for right-wing Latin dictators. On the other hand, it may be that human rights, because of the courage of people who insist on them -- like Kim and Chileans who march in the streets against torture - is cause that cannot be be suppressed.