The Man with Two Names

Song Du Yul returned to his homeland of South Korea last week, after 36 years of political exile in the West, to a surprising welcome: South Korean intelligence officials declared that Song may be a top North Korean spy.

In 1967, the student activist moved to Germany and became a philosopher and sociology professor, whose books and newspaper columns full of sympathetic accounts of North Korea's leaders were de rigeur reading on South Korean college campuses. Two National Intelligence chiefs and a Unification Minister have claimed in national-assembly hearings that Song went further: that he became the 23rd-ranked...