The Warrior Ethos, by Steven Pressfield (Black Irish Entertainment, 2011)

An overview of Spartan military and related philosophies. A clear and straightforward introduction, intended both as a primer for soldiers and to those addressing other conflict areas (creative struggles, etc). Useful and direct, not least if you appreciate the same author’s fiction and wider writings on creativity.

My own books are here, if that’s your thing. Newest is noir thriller East of England.