According to me, if we use Military history to learn about leadership and study the commander's mind then it will be the more constructive approach towards the subject. We can keep our focus on military affairs which have large impact on our society.
Military history as a discipline record the armed conflict in the history of humanity and tries to assess it's impact over economies, societies, culture, etc. which in result lead to changes or development in local and international affairs. It also help us to study about military strategy adopted by each side and help in assessing how these tactics and technologies have changed with time, for example, it tries to explain that how warfare led to the development of weapon and with time how emerging technologies have shaped these weapons.
