Why did Soviet leaders not resort to force to preserve the Warsaw Pact in 1989? This article provides a cognitive model of how decision-makers learn from experience. It seeks to specify and establish the causal effect of this mechanism (elite cause-and-effect learning) as opposed to alternatives (more materialist or normative arguments) and to lay out the scope conditions for its operation. Soviet leaders learned from past Soviet military interventions in Czechoslovakia, in Afghanistan, and elsewhere the high costs and negative consequences of the use of force. Even Soviet hardliners, for both material and ideational reasons (i.e., beliefs about the efficacy of force), would have hesitated about the use of force in Eastern Europe had they been in power. The hardliners did, however, have much different views about the terms the Soviet Union should seek regarding German unification. Gorbachev's ideas prevailed largely because of the lingering authority of his position as top leader. In short, although ideas and material constraints pushed in the same direction to produce the startling events of 1989, ideas and governmental structure were critical in determining which of competing policy prescriptions would prevail regarding German unification.