Babić became a military cadet in the Yugoslav Royal Army and was sent to Paris to perform further training at the École Superieure de Guerre.

[1] During the German-led attack on the Kingdom of Yugoslavia, Babić served as a major in the 38th Drava Infantry Division.

[citation needed] In 1942, he commanded the 369th Reinforced Infantry Regiment, commonly known as the Croatian Legion, which fought on the Eastern Front.

Later that year, Babić became a conspirator in the Lorković–Vokić plot and flew a mission to American troops in Italy to suggest that the Allies invade the Dalmatian coast of the Independent State of Croatia to prevent the country from falling into communist hands.

[3] He secured a visa for Croatian writer Bruno Bušić to come to Spain; Busić was later assassinated.