Military science is tactics elevated to the highest possible level, a level almost as sophisticated as one of the real sciences. It encompasses not only the study of modern weapons (since these are advancing at an unbelievable pace, making it a frequent occurrence a weapon a cadet studied to become obsolete right after he finishes school), but also of employing the terrain to one's advantage, using transport and logistics (and denying the enemy their use), etc. etc. And it emphasizes something the good general knows instinctively - how important organization and discipline are on the field.