This lesson is about nuclear proliferation. The role play has students examine mutually assured destruction. As the US or Soviet Union, they must predict how they and their opponent would act in a situation where the Berlin blockade/airlift lasts 4 months longer until the Soviets successfully test a nuclear bomb, and then shoot down US planes because they are not afraid of the US nuclear advantage. Most students get to the point of seeing how nuclear weapons will be used by both sides, and thus understand the MAD theory. The article mentioned in the do now is also included.