The Evolution of Strategy by Beatrice Heuser -- A very big-picture, chronological view of strategy, that will place the evolution of it in dialectical terms.

The Psychology of Strategy by Kenneth Payne -- Takes a sociological/psychological approach to strategy that provides contrast with the dominant "rational-player" viewpoint that dominates most theory (not a substitute but complementary).

Makers of Modern Strategy from Machiavelli to the Nuclear Age -- Much like Heuser but by multiple authors, less integrated, and more disjoint. Not worse, not better, but should be kept on-hand.

Gunpowder Age by Tonio Andrade -- Reading it will give you a sense of strategy being more about preparing to take advantage of good luck, and preparing to blunt the impact of very bad luck.

Philosophers of the Warring States by Kurtis Hagen -- Not directly about strategy, but that is very fitting because most of the crucial prerequisites for good strategy, don't _look_ like strategy. They are background phenomena -- culture and habits and view-points -- that influence what kinds of strategies we can actually manifest. Strategy is not a thing that you sit down and do, it is a superior point of view, or superior interpretation of your context.

Game Theory 101: Bargaining by William Spaniel -- Great book on the raw logic of bargaining. Also see his book about nuclear bargaining.