Nuclear Brinkmanship, Limited War, and Military Power*

An open question in nuclear deterrence theory is whether and how the balance of military power affects the dynamics of escalation. The balance of military strength plays virtually no role in standard accounts of brinkmanship. But this largely by assumption and seems incompatible with an apparent trade-off between power and risk that decision makers faced in some actual crises. This paper incorporates this trade-off in a modified model of nuclear brinkmanship. One of the main results is that the more likely the balance of resolve is to favor a defender, the less military power a challenger will bring to bear. The model also formalizes the stability-instability paradox, showing that a less stable strategic balance, i.e., a sharper trade-off between power and risk, makes conflict at high levels of violence less likely but conflict at lower levels more likely. The analysis also helps explain the incentives different states have to adopt different nuclear doctrines and force postures. * I am grateful for helpful comments, criticisms and discussion from Andrew Coe, Alexandre Debs, Sumit Ganguly, Charles Glaser, and Neil Joeck. † Travers Department of Political Science, UC Berkeley. [email protected]. Nuclear Brinkmanship, Limited War, and Military Power Many argued during the cold war that the balance of conventional power between NATO and the Warsaw Pact was not very important. Deterrence between nuclear states depended on the balance of resolve, i.e., on the states’ relative willingness to run the risk of nuclear escalation, rather than on the balance of military strength.1 Even if the balance of military power between the United States and the Soviet Union was relatively unimportant given those states very large nuclear arsenals and the risks inherent in them, what of the balance between India and Pakistan, the United States and China, or the United States and a nuclear-armed Iran? Posing the question more generally, how does the balance of military power between two nuclear states affect deterrence and the dynamics of escalation? As elaborated below, the balance of military power does not matter much for deterrence in the theory of nuclear brinkmanship. Indeed, the balance of power plays virtually no role in the logic of brinkmanship. It is however hard to reconcile this aspect of the theory with key features of actual crises. For example, states in the midst of a nuclear crisis frequently appear to face a fundamental trade-off between bringing more military power to bear and raising the risk of escalation to nuclear war. When deciding whether or not to escalate, a state can often take steps that more fully exploit its military capabilities and potential. This increases the chances of prevailing if any subsequent fighting remains limited and the conflict does not escalate to a catastrophic nuclear exchange. But these steps also make it more likely that the crisis will ultimately end in this way. India faced this trade-off between power and risk in the Kargil War. In early 1999, Pakistani troops surreptitiously crossed the Line of Control (LoC) and took up fortified positions overlooking India’s National Highway-1A , the key supply route for Indian forces on the Saichen Glacier. India learned of the incursion in early May and launched an attack to expel the Pakistanis. Concerned about possible escalation, Indian authorities made 1 See for example Jervis 1979-80, who is quoted below, as well as Schelling 1966; Jervis 1984, 1989; Bundy 1988, and Glaser 1990.