The book has had a good reception, and many have cheered me by telling me they liked it or learned from it. But the response that warms me most after twenty years is the late John Strachey’s. John Strachey, whose books I had read in college, had been an outstanding Marxist economist in the 1930s. After the war he had been defense minister in Britain’s Labor Government. Some of us at Harvard’s Center for International Affairs invited him to visit because he was writing a book on disarmament and arms control. When he called on me he exclaimed how much this book had done for his thinking, and as he talked with enthusiasm I tried to guess which of my sophisticated ideas in which chapters had made so much difference to him. It turned out it wasn’t any particular idea in any particular chapter. Until he read this book, he had simply not comprehended that an inherently non-zero-sum conflict could exist. He had known that conflict could coexist with common interest but had thought, or taken for granted, that they were essentially separable, not aspects of an integral structure. A scholar concerned with monopoly capitalism and class struggle, nuclear strategy and alliance politics, working late in his career on arms control and peacemaking, had tumbled, in reading my book, to an idea so rudimentary that I hadn’t even known it wasn’t obvious.

Thomas Schelling, The Strategy of Conflict, Cambridge, Massachusetts, 1960, pp. vi-vii [‘Preface to the 1980 edition’]