Nonnuclear weapons are increasingly able to threaten dual-use command, control, communication, and intelligence assets that are spaced based or distant from probable theaters of conflict. This form of “entanglement” between nuclear and nonnuclear capabilities creates the potential for Chinese or Russian nonnuclear strikes against the United States or U.S. strikes against either China or Russia to spark inadvertent nuclear escalation. Escalation pressures could be generated through crisis instability or through one of two newly identified mechanisms: “misinterpreted warning” or the “damage-limitation window.” The vulnerability of dual-use U.S. early-warning assets provides a concrete demonstration of the risks. These risks would be serious for two reasons. First, in a conventional conflict against the United States, China or Russia would have strong incentives to launch kinetic strikes on U.S. early-warning assets. Second, even limited strikes could undermine the United States' ability to monitor nuclear attacks by the adversary. Moreover, cyber interference with dual-use early-warning assets would create the additional danger of the target's misinterpreting cyber espionage as a destructive attack. Today, the only feasible starting point for efforts to reduce the escalation risks created by entanglement would be unilateral measures—in particular, organizational reform to ensure that those risks received adequate consideration in war planning, acquisition decisions, and crisis decisionmaking. Over the longer term, unilateral measures might pave the way for more challenging cooperative measures, such as agreed restrictions on threatening behavior.
Escalation through Entanglement: How the Vulnerability of Command-and-Control Systems Raises the Risks of an Inadvertent Nuclear War