This module is designed to apply mathematical models to nuclear deterrent problems, and to aid users in developing enlightened skepticism about the use of linear models in stability analyses and long-term predictions. An attempt is made at avoiding overwhelming complexities through concentration on land-based missile forces. It is noted that after the Second World War, the United States' monopoly on nuclear weapons permitted it to attempt to deter aggression through a policy of "massive retaliation." The history of change from this policy is outlined, and the chances for reaching an equilibrium in the nuclear arms race are examined through probabilistic models. Exercises are provided, and the answers to these problems are given at the end of the unit. (MP)