Stephen L. Carter talks about his new novel Back Channel, a retelling of the Cuban Missile Crisis. The novel goes back to October 1962, when the Soviet Union smuggled missiles into Cuba. Kennedy and Khrushchev are in the midst of a military face-off that could lead to nuclear conflagration. Both leaders are surrounded by advisers clamoring for war. The only way for the two leaders to negotiate safely is to open a surreptitious path of communication.