Having been brought up in New York, Per was strongly anti-communist and saw Stalin as a bigger threat to Norway than Hitler. Consequently he fought for the Germans in WWII and stoically accepted the prison sentence he was given after the war.

Jo told the London Guardian in May 2014:  "My father was 18 when the war started, and shortly after German troops occupied Norway on 9 April 1940, he was arrested for writing politically provocative things about Hitler on his desk in school. He was thrown in jail, but a year later he volunteered to fight the Russians on the eastern front. At that same time, my mother was a young girl running errands for the resistance movement."