KITAKYUSHU -- On Aug. 30, 1993, four North Korean agents slipped over the 38th parallel into South Korea. Disguised as South Korean soldiers, their mission was to spy on U.S. and South Korean forces near Panmunjun.

Five days later, one of the agents walked into a South Korean military command post and surrendered, asking for -- and receiving -- asylum.

"It was because of my spy training that I decided to seek asylum. I had infiltrated South Korea previously and saw, contrary to what we were taught, that it was far more free and prosperous than North Korea," said former agent An Myong Jin during an interview with The Japan Times.