Continue on with analysis of repeated games: tit for tat strategies, the "grim" strategy. Threats and promises may need to be made credible. We start with a simple 2x2 sequential "threat game", identify the credibility problem, and then see how it is resolved in a clip from a classic cult movie Dr Strangelove, available on a new special edition DVD. Fred Kaplan has an excellent review of this movie here.The lecture ends with a brief examination of the 10 methods for achieving credibile threats promises and comittments from Dixit and Skeath ch10.