SEOUL — Earlier this year, one of the most prominent North Korean defectors, Yoo Woo-sung, walked out of his apartment building here and found four South Korean government vehicles waiting for him.
Authorities hauled Yoo away and arrested him on charges of espionage. They had learned of his alleged crime, court documents show, thanks to testimony from his sister, who said Yoo had been sent on a mission by North Korea’s secret police to infiltrate the defector community and pass back information about the people he met.
Yoo, 32, is being held at a detention center on the outskirts of Seoul, his case a reminder of how this peninsula’s messy and sometimes covert conflict has left the South on edge, with people here unsure whom they can trust.
Defectors from the North are increasingly facing the brunt of this suspicion. As more flee to the South — some 25,000 in total, nearly all coming in the past two decades — South Korean analysts and government officials say the North has expanded a program used to sow anxiety and collect information, both by disguising spies as defectors and by pressuring defectors to become spies after they arrive. The South, in turn, has raised its guard about those entering the country, changing its protocol three years ago to allow for lengthier interrogations of arrivals from the North.