Secretive, mysterious, and almost certainly dangerous, North Korea is an object of endless fascination--and worry--for the rest of the world. The world's most inaccessible nuclear power, it retains Gulag-style prison camps, completely blocks Internet access, and forbids citizens to talk to foreigners without approval--which makes the occasional report from a smart, dogged, connected analyst all the more valuable.

North Korea: State of Paranoia is just such a report. Drawing on an impressive range of insider sources and previously unseen archival material, Paul French examines the...