Two years in production. This was mostly due to delays caused by a suspicious South Korean government, and the need to fight off rival interested parties. Other complications including the complete non-involvement of anyone from the North Korean side and from the CIA who were known to be actively involved in the debriefing of Choi Eun-hie and Shin Sang-ok but continually denied any involvement.
Jong-Il Kim was a huge film fan and had over 15,000 movies in his private collection. The bulk of these were not homegrown North Korean productions which he felt were stiff and lifeless (they were propaganda of course). Instead Kim admired the more dynamic productions from South Korea and the West even though he had banned these from being shown.
The illicit tapings that Choi Eun-hie and Shin Sang-ok took of their meetings with Jong-Il Kim - and which ultimately lent credence to their outlandish story - was one of the first times that dictator Kim's voice was heard in the West.
Ross Adam became interested in the story of the kidnapping because it seemed too outlandish to be real.