When World War II reached Norway in 1940, he fought for his country as part of the Norwegian Campaign.
[3] After fleeing again, to England, in January 1944 via Sweden, he received parachute training and returned to Bærum.
[1] Thurn-Basberg was then in charge of the radio station Gullfaks, named after Gullfaxi of Norse mythology.
[4] He especially became known for a telegram sent in June 1944, where he described how the Wehrmacht believed false reports that the Allies were planning an invasion in central Norway, and thus kept large German forces away from the actual war theatre in continental Europe.
In his civil life he worked as a small-scale businessman, with import of French wine (inherited from his father) as well as miscellaneous gas station equipment.