The National Defence University of Warsaw (Polish: Akademia Obrony Narodowej – AON) was the civil-military highest defence academic institution in Poland, located in Warszawa–Rembertów. In 2016 it was succeeded by the War Studies University. The school's master's program was a five-years study program, but also AON provided two-years under- and over graduate study programs and four-years PhD (Doctor of Science) programs and higher doctorate (habilitation) opportunity as well.