 In April 1941 following the Axis invasion of Yugoslavia and Greece, Jovanović wanted to join the army, but was rejected under suspicion of anti-state activities having been a Revolutionary suspect in the so-called "White Terror" of King Alexander during the 1930s, and later, Prince Regent Pavle.Three months later, after joining the Partisan movement led by Josip Broz Tito, he is reputed to have started the war against fascist occupiers.On July 7, 1941, he shot two members of the Quisling Serbian State Police, or gendarmerie, at a fair in Bela Crkva.