On the face of it, Kim Dae Jung's announced plan to return to South Korea, where advocates of democracy like himself are regarded as traitors, seems suicidal folly.

One has only to think of the shower of bullets that met Benigno Aquino, the Philippine foe of the Marcos government, when he stepped off a plane in Manila in August 1983 to realize what a chance Kim is taking with the iron-fisted dictator who runs his native land.

But Kim is going home, probably in early February, although certainly not on a Korean Air Lines plane. He speaks confidently, in halting English, about his hope of having a dialogue with President Chun Doo Hwan, the general who seized power in May 1980 and who had Kim sentenced to death a short time later.

Kim, 58, who walks with a cane because of infirmities incurred during 5 1/2 years of prison, has escaped death at the hands of Korean authorities on five occasions.

One rescue he attributes to divine intervention. He was kidnaped by the KCIA in Tokyo, then taken to sea. At the moment Kim's abductors were about to throw him overboard, a U.S. plane buzzed the boat and frightened off his captors.

He has also been saved by two American presidents. In 1978, he was released from prison -- his crime was organizing and signing a Declaration for National Democracy -- as a condition for a planned visit by President Jimmy Carter to South Korea. In 1981, President Reagan got Kim's death sentence commuted, and he finally wangled Kim's release from prison in 1982. Kim then came here for medical treatment, attended Harvard and tried, in vain, to change U.S. policy toward Korea.

Despite the fact that he is living proof that "quiet diplomacy" works, Kim says it is not enough.

"If the U.S. is for human rights and democracy," he said during an interview, "You must let my people know. You have to have open diplomacy, too."

That point was recently brought home strongly by Bishop Desmond Tutu of South Africa, who came through here and reproached Reagan for his policy of "constructive engagement" with the South African government. He created such a stir that Reagan broke a four-year silence about the evils of apartheid.

The bishop's trump was his Nobel Peace Prize, which focused world attention on the agony of his homeland and reinforced his considerable moral authority.

Kim has a trump card, too, as he goes to confront a leader who seems to be holding the whole deck -- the 600,000-man South Korean Army, the KCIA and the backing of the Reagan administration, which has praised the Korean government for small steps in liberalizing a rule that forbids political parties and freedom of the press.

Unlikely as it seems that the general would stoop to parley with a poor convict, Kim thinks that it will happen. Although Korea, with the exception of the campuses, is moderately calm and extremely prosperous, Kim says that riot police are ever on the watch in Seoul and that the smell of tear gas is often in the air.

That will not do during the Olympics, which are scheduled for Seoul in 1988. Kim contends that the majority of the Korean people want democracy -- he came within four points of winning the presidency in 1970 -- and will not rest until they achieve it. Any kind of demonstrations, with the savage countermeasures the Korean police never hesitate to take, would make the rest of the world nervous for its athletes.

Kim is hoping to fly home with a large foreign delegation aboard to witness his arrival and the treatment accorded to him, assuming he survives the landing. Patt Derian, who vigorously served the Carter administration as assistant secretary of State for human rights, has agreed to go. Other notables, such as Mike Farrell, the "M*A*S*H" star, have expressed interest.

The Korean ambassador here has indicated the fury of his government at the prospect of Kim's homecoming. After Sen. Edward M. Kennedy (D-Mass.) wrote Chun, asking him to ensure Kim's safety and to grant him amnesty, the ambassador told Kennedy that Kim would be expected to serve the 17 1/2 years remaining on his 1980 sentence -- even though his co-defendants have been unconditionally released.

Kim says he does not expect to land back in a dank Korean jail. He thinks imprisonment could prompt "a serious uprising" in Korea and a "grave international problem."

House arrest he is prepared for. It would keep him under wraps, but Koreans would receive the "powerful emotional message of my return."

Kim is going, probably in the first week of February. He thinks he belongs in Korea, with his people. And with the world looking on, fretting over the well-being of its treasured athletes, he thinks he may safely resume his dangerous work of trying to make it a more democratic society.