Warning Systems and Defense Policy: A Reliability Model for the Command and Control of U.S. Nuclear Forces

The U.S. Command, Control, Communication and Intelligence System (C3I) includes sensors (e.g., satellites and radars), communication links, and computer systems that allow gathering and processing of information that a missile attack on the continental United States may be on the way. The choice of a policy of response to such an attack depends in part on the reliability of the information coming from the C3I. We consider in this study four possible response policies: (1) launch on impact, (2) launch on attack assessment, (3) launch under attack, and (4) launch on warning. We propose a method to compute, for each policy, the probability of accidental nuclear strike and the probability of being unable to respond due to a malfunction of the C3I or to partial destruction of the response forces. We include in our system the launch authorization steps (permissive action links) and a very crude analysis of the survivability of second strike forces. We examine the variations of probabilities of Type I and Type II errors and the tradeoffs involved when shifting from a policy of launch on impact to another launch policy. We conclude that this simple but powerful method allows one to gain a good grasp on some of the complex issues involved.