WAR: perhaps the greatest, most comprehensive book written on this topic
Dyer precisely explicates the role of the soldier: "You offer yourself to be slain: This is the essence of being a soldier. By becoming soldiers, men agree to die when we tell them to."

Available at Amazon

Dyer's fantastic seven-part video series begins here.

His website is here: 2,089 articles containing 1,884,414 total words!