A deterrent threat meets this definition nicely; it works only because of what the other player expects us to do in response to his choice of moves, and we can afford to make the threat only because we expect it to have an influence on his choice. But in international strategy the promise of game theory is so far unfulfilled. Game theory has been extremely helpful in the formulation of problems and the clarification of concepts, but its greatest successes have been in other fields. It has, on the whole, been pitched at a level of abstraction where it has made little contact with the elements of a problem like deterrence.

DEFINE: Clarifies what a deterrent threat is and why game theory fits it conceptually yet fails practically.

Thomas C. Schelling, The Strategy of Conflict, loc. 30