Gates of Fire - An Epic Novel of the Battle of Thermopylae
Three hundred Spartans hold of an army of nearly two million Persians at a narrow mountain pass. Lots of historical accuracy (accounts from Herodotus). Spartans gave the Greeks enough time to hold off Persaians and preserve Athens and early Western democracy...
Oddly enough, it's by Steven Pressfield, who wrote The Legend of Bagger Vance.
John Stuart Mill: "War is an ugly thing, but not the ugliest of things. The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself."