Complex sentence: Although all of the European powers were unprepared for modern air warfare in the beginning of the conflict, Austria-Hungary was one of the most disadvantaged due to the empire's traditionalist military and civilian leadership combined with a relatively low degree of industrialisation.
Split into simpler sentences: Although all of the European powers were quite unprepared for modern air warfare in the beginning of the conflict, Austria-Hungary was one of the most disadvantaged. This was due to the empire's mostly traditionalist military and civilian leadership combined with a relatively low degree of industrialisation.