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Are there any Warrior-Philosophers I can read?(r/askphilosophy)
You mentioned Sun Tzu, which is a great start. If you’re into warrior philosophers, or as close as we get to it, maybe the Stoics would be good. In particular check out Marcus Aurelius’s Meditations and Cicero’s De Finibus. I’m not sure how much action they saw, but they both lived as ~~emperors~~ statesmen in Rome. They’re not explicitly concerned with war alone, but it influenced some of their views.
For an overview of how philosphers look at war, check out Orend’s piece from the Stanford Encyclopedia of Philosophy. If you’re looking for a more detailed treatment of death and war, I’d check out Jeff McMahon’s Killing in War, which is a contemporary work by a respected philosopher. For a more psychological approach where a philosopher looks at the effects of war, I’d recommend Nancy Sherman’s, The Untold War.