Military history provides the required context, width, and depth to understand past ways and means in the absence of physical combat experiences. It allows professionals to test their knowledge and ideas against a framework of historical military experience. It also provides insights into successful methods and permits learning through vicarious failure.  The study of history can also, as Richard Neustadt and Ernst May argue in Thinking in Time, stimulate imagination by seeing the past as a way to better envision the future.

Michael Howard has proposed the most compelling reason for studying military history is that unlike other enduring professions, the military profession is intermittent. In essence, military history is the case law for military professionals to prepare for future operations.  And as Howard has also noted, military professional must hone “the ability to look at the past to see what works and what does not … the last war provides the only firm data that they have.” Military history provides an intellectual foundation for dealing with the ambiguity, uncertainty, and friction inherent in war…

via Mastering the Profession of Arms, Part III: Competencies Today and into the Future — War on the Rocks

All around excellent article. I wish I would have read it twenty years ago.