Jürgen Habermas acted as his thesis advisor; he was also heavily influenced by the ideas of Peter Christian Ludz [de].
[1][2] He organized a total of six conferences for Korea's reunification in Beijing (1995–1999) and in Pyongyang (2003), attended by scientists from both parts of the divided county and from abroad.
[citation needed] Song attempted to make arrangements to travel to South Korea in May 2000 to attend memorial events commemorating the 20th anniversary of the Gwangju uprising.
[3] In 2001, North Korean defector Hwang Jang-yop asserted that Song was actually a member of the Workers' Party of Korea's Politburo under the alias Kim Chol-su.
[1] However, upon his arrival, the National Intelligence Service immediately picked him up for interrogation; they accused him of being a spy for North Korea, pointing to Hwang's claim that he was actually Kim Chol-su as justification.
[5] Pyongyang initially refrained from comment on the trial, sparking speculation that Song had cut his ties with the North; however, the official Korean Central News Agency eventually came out with harsh criticisms of the trial in 2004, calling the Grand National Party "traitors to the nation" for taking the lead in the legal action against Song and accusing the South of violating the June 15th Joint Declaration by charging him under the National Security Act.