 A reserve officer in the Belgian Army, he was briefly held in a prisoner-of-war camp following the German invasion.Despite his reservations, Streel was ultimately reconciled to collaborationism, fearing that the alternative would be German annihilation of Belgium.He became editor of "Le Pays Réel" in August 1940 when it re-appeared and, with Degrelle enlisting in the German forces, he became an important advisor to the new Rexist leader Victor Matthys.