Because of his great popularity, the Nazi regime called on him after the start of World War II to sing on the popular radio music show Wunschkonzert für die Wehrmacht (Request Concert for the Armed Forces), where he was particularly renowned for his rendition of Gute Nacht, Mutter (Good Night, Mother) by Werner Bochmann. From 1940, he recorded various other war songs as a soloist. He also appeared in the propaganda films Wunschkonzert (1940) and Fronttheater (1942).Ernst Klee: Das Kulturlexikon zum Dritten Reich. Wer war was vor und nach 1945 (The Cultural Lexicon of the Third Reich. Who was who before and after 1945). S. Fischer, Frankfurt am Main 2007, S. 600. In the final phase of the Second World War, Adolf Hitler included Strienz in the Gottbegnadeten list (list of those graced by God) as one of nine major concert singers in August 1944, exempting him from military service during the final stages of the war.
