Striden om norsk NATO-medlemskap innen regjeringspartiet 1948–49, which was released in 1972 and explores objections to NATO membership within the Norwegian Labour Party (DNA).
In 1987 he wrote Frigjøring, volume eight of the World War II work Norge i krig, with Terje Halvorsen.
In 1998 he released a two-volume history on surveillance in Norway, Den hemmelige krigen: overvåking i Norge 1914–1997, together with Trond Bergh.
Former secretary of the Standing Committee on Finance and Economic Affairs Haakon Bingen sued Eriksen and Bergh as well as the publishing house Cappelen Akademisk Forlag, because the second volume of Den hemmelige krigen contained information that portrayed Bingen as a close friend of communist Peder Furubotn.
In late 1999 the Supreme Court of Norway found that this was not true, and circulation of the book was forbidden, until the reference to Bingen had been amended.