During the German-led invasion of Yugoslavia in April 1941, Galić serving with the Mostar-based III. PS. The following month, Galić flew to Sinj where he joined the newly formed Air Force of the Independent State of Croatia. He joined the Croatian Air Force Legion and went to Fürth near Nürnberg for special training before going to the Eastern Front as part of 15 (kroat.)/JG 52, a Croat "staffel" attached to Jagdgeschwader 52 of the Luftwaffe. Flying a Bf 109E-4, he scored his first victory on 2 March 1942, a R-10 shot down over Magnitovka.