Strategy classics

In reading Securing Japan I thought Richard Samuels summed it up quite nicely (pp. 109):

There are few truly new ideas about how nations can protect themselves. Each country is armed with its military, its diplomats, its mix of resources, its ambition, and its wits. The rest is, as ever, derivative. This is why students studying international relations, diplomacy, and national security are still required to read The Peloponnesian War by Thucydides, The Art of War by Sun Tzu, and Machiavelli’s The Prince. Ideas about strategy endure because geography, demography, and technology endure as constraints on the ability of leaders to make their people prosperous and safe. But if there are few original ideas about strategy, there are limitless combinations of existing ones. Because the balance among constraints is always in motion, and because the power of neighbors rises and falls, new circumstances always await the application of old ideas. Contexts change, but ideas endure.

QED, see the reading list from my first year of War Studies.