Weaponry tends to dominate discussions of nuclear war. Missiles and bombers, throw weights and flight times, and the elaborate counting rules of arms-control agreements provide the grist of public debate. After the weapons themselves come the plans for their use, bearing such names as minimum deterrence, flexible response and countervailing strategy. Weapons and strategic doctrine are meaningless, however, unless the superpowers also have the means to know what is happening in the chaos of crisis or war, to provide for decisions by legitimate authorities and to have orders carried out precisely and faithfully. In military parlance these capabilities form the system of strategic command, control, communications and intelligence, or C3I (pronounced "see cubed eye"). Although C3I has been largely neglected outside a narrow circle of experts, it is an allimportant facet of the problem of deterring nuclear war, fully as important as weapons and doctrine.
Carter, Ash. “Command and Control of Nuclear War.” Scientific American, January 1985