Complex sentence: In the aftermath of World War II and the seizure of power by the Yugoslav Partians, Josip Broz Tito's communist Yugoslavia repressed nationalism of any culture that was deemed to be a threat to the state.
Split into simpler sentences: In the aftermath of World War II and the seizure of power by the Yugoslav Partisans, Josip Broz Tito's communist Yugoslavia was established. The new regime repressed nationalism of any culture that was deemed to be a threat to the state.