''When we were growing up, we were told that we had to sacrifice for our country,'' said Jonathan Kim, 43, chief executive of Hanmac Films and a producer of the movie. ''Not only physically, but also in the area of human rights. We were told to ignore these things because of the Communist threat. Now we can see what our government did and what was sacrificed.''

The movie, based on a magazine article and a book on the subject, could not have been made, Mr. Kim said, until the recent reconciliation between the North and South under the ''sunshine policy'' of South Korea's former president, Kim Dae Jung. Before, merely playing a North Korean song in the movie would have caused trouble with the authorities.

Yang Dong Su, 54, is one of six guards who survived the Silmido uprising. Like the other survivors who have been talking to the media here, he confirmed that Unit 684's mission had been to infiltrate North Korea and kill Kim Il Sung.

Now a high school teacher in Seoul, Mr. Yang was sent to Silmido in October 1970 to serve out his military duty. Although the movie portrays the 31 recruits as death-row convicts given one last chance to redeem themselves, Mr. Yang said most were petty criminals.

''They were the kind who would get into street fights a lot,'' he said in an interview in Seoul.

Most had been promised jobs and money if they succeeded, Mr. Yang said. But after the mission was canceled, they were kept in limbo.

What led to the uprising on Aug. 23, 1971, is unclear. The movie shows the government deciding that the recruits had to be killed because they knew too much. The recruits find out and revolt. (Mr. Kim, the producer, acknowledges that history is not clear on that point.)

Mr. Yang has a different view. ''They revolted because they felt that they were never going to get the chance to go to North Korea and that they would never be allowed to leave the island,'' he said. ''They were in despair.''