Edward Coffman, a former military historian at the University of Wisconsin, studied the 25 best history departments according to U.S. News & World Report rankings and found that a mere 21 professors out of more than 1,000 listed war as their specialty. A Notre Dame student complained recently: "We have more than 30 full-time history faculty members, but not one is a military historian. Even in their self-described interests, not a single professor lists 'war' of any era, although half list religious, gender and race relations."
Quite sad especially when one considers the times we live in today. Learning about and understanding previous wars makes us comprehend the present global conflict at a much better level.
For example, Winston Churchill's The Second World War (a six-volume set) is a magnificent place to start. It's scary how some of the appeasement rhetoric of the 1930s is being used today. Historically ignorant people continue to "think" that if only we were to leave the Jihadists alone, we'll have peace. You see, they've seen the warmongers and they are us. Churchill detailed this pathology in the first volume. In the rest, we see the bloody consequences.
Another relevant book is Donald Kagan's The Peloponnesian War (the world war of the ancient world). Many people who read it take the lesson that a democracy can be defeated. My reaction was a little different. I was amazed at just how much effort and resources it took to finally beat Athens: the two kings of Sparta leading massive Greek armies (for its time), the rebellions in the Empire and the bankrolling by Persia.
One also learns a lot about humanity from this. We can be extremely fickle and short-sighted when blood is being spilled. We'd rather grab on to a momentary pause in conflict rather than truly finish a war. That peace is often a cruel illusion.