Estimates have been made of the numbers of weapons available for retaliatory attack under four possible force structures for each state.  For the United States, the four structures include: a balanced triad of ICBMs, SLBMs and bomber delivered weapons; a dyad without ICBMs; a dyad without bombers; and a force based entirely on SLBMs.  For Russia, the four force structures include: a balanced triad; a dyad of ICBMs and  bombers; a dyad of ICBMs and SLBMs; and a force made up entirely of ICBMs.  The alternatives to triads for each country reflect differences in their force modernization priorities based on past experience: ICBMs for Russia, and SLBMs and bombers for the United States.  Current U.S. and Russian modernization plans call for continued modernization of triads; hypothetical alternatives are included for comparative purposes.

In the canonical case often used for analysis (but not necessarily reflecting the likelihood of actual operations), either an American or Russian strategic nuclear triad, under conditions of “generated alert, riding out the attack,” could provide for more than 500 retaliating weapons under a deployment limit of 1,000 warheads.  For a deployment limit of 500 warheads, a U.S. retaliatory triad on generated alert and riding out the attack could provide more than 300 surviving and retaliating weapons; under the same conditions, a Russian triad would yield more than 200 retaliating warheads.

Objections to minimum deterrence. Objections to the preceding analysis and argument can be anticipated along the following lines:

First, China might not play. Unless and until China feels it has an essential nuclear-strategic parity with the United States and Russia, Beijing might be disinterested in nuclear arms control. On the other hand, this objection might apply only or mainly to the bean-counting aspect of nuclear force reductions and to required inspections.

The United States and Russia would benefit from including China in multilateral discussions about the nature of strategy and strategic thinking, about threat perceptions and the international environment, and about the need for international collaboration on issues including nonproliferation and nuclear risk reduction. Eventually China might find a comfort zone as one of the Big Three nuclear weapons states, appreciate the symbolic and substantive benefits of sharing arms control preeminence in international forums, and conclude that it would be smarter to be included in the arms control tent than standing apart from it.

China can be expected to ease into nuclear arms control gradually – unaccustomed as China is to the transparency required for arms limitation and reduction talks. Nevertheless, China could eventually decide that the alternative to participation would be an apparent obliviousness on the part of its leadership to the possibility of an uncontrolled nuclear arms race.

Part of the concern about a rising nuclear China is the fear that China and Russia might combine their strategic nuclear forces and pose an insuperable threat to current plans for US nuclear modernization. In a worst case of deterrence failure, the United States could find itself attacked simultaneously in Europe and in Asia by large scale conventional forces supported by the implicit or explicit threat of a joint Sino-Russian resort to tactical or strategic nuclear weapons. On the other hand, it cannot be assumed that an outbreak of wider war in Europe would necessarily cause China to combine with Russia under all circumstances. Nor would Russia necessarily come to China’s aid in case of a crisis in Asia. Much would be circumstantial with respect to each side’s political motivations.

A second objection to minimum-deterrence proposals might come from military planners and those who make decisions about nuclear employment policy. Would a minimum-deterrence regime permit the United States to field a force that provided for more flexible options than a one-variety “wargasm” that limited policy makers’ range of choices under exigent conditions of deterrence failure?

The answer to this concern is that, so long as the US arsenal is capped at the same number as those of potential adversaries, no single power should be disadvantaged relative to the others with respect to its capabilities for flexible targeting and escalation control. In fact, compared to the strategic nuclear forces of Russia and China, the United States’ would provide more flexibility than those of Russia or China because more of the US deterrent resides on ballistic missile submarines, the most survivable leg of any strategic nuclear triad. In theory, Russia and China might gang up on the United States and grossly outnumber the Americans in operationally deployed weapons. In practice, however, it is difficult to imagine either Russia or China riding the coattails of the other party into a holocaust—even under the best of conditions for them.

A third objection to a minimum-deterrence regime for strategic nuclear forces is that it does not deal with the problem of nonstrategic nuclear weapons. The concern is well placed, but nonstrategic nuclear weapons come in so many varieties that separate negotiations will be needed to agree a formula among the United States, Russia and China, as well as among other nuclear weapons states or aspiring NWS. But the United States and Russia should prioritize bilateral talks about what to do with nonstrategic nuclear weapons now deployed in Europe.

A fourth concern about the preceding analysis is that it does not provide any prescription for preventing the rise of new nuclear weapons states, especially those with revisionist aims relative to the existing international order.[8] Guilty as charged. A nuclear Iran is the most immediate worry here, but also, additional misbehavior by North Korea that encourages South Korea, Japan, or other American allies in Asia to become nuclear weapons states.

No magic bullet is offered here to guarantee against an expanded club of nuclear weapons states. But a combination of good example set under a minimum-deterrence regime—with successful deterrence or other persuasion against additional nuclear weaponization—is one possible pathway to reviving an otherwise endangered nonproliferation regime.[9]

One option for avoiding a nuclear arms race. Minimum deterrence is a concept, and the need for adaptive concepts is urgent because the international system has changed significantly since the end of the Cold War. Minimum deterrence may be a practical consolation prize for advocates of nuclear abolition or, at the same time, a symbol of US nuclear stasis or decline for those favoring more ambitious strategies.[10] At the very least, minimum deterrence should contribute to serious discussions about limitations in strategic nuclear force sizes among the United States, Russia, and China. An unlimited arms race only invites instability.

In addition to the challenge of “how much is enough” with respect to nuclear weapons and launchers, minimum deterrence will also have to adjust targeting plans to fit the new technological environment of the 21^st century. Weapons for destruction of “war supporting industry” or national economies will be less relevant than the ability to disable or destroy the sinews of state political control and the brain and central nervous system of armed forces. Therefore, the earliest strikes will likely be made against cyber systems and space-based assets for reconnaissance and warning, navigation, C3 (command, control, and communications), and other vital military functions.

Finally, experts disagree about whether nuclear superiority correlates with favorable outcomes in coercive bargaining between rivals. For example, University of Virginia expert Todd S. Sechser and Teas A&M political scientist Matthew Fuhrmann argue that “states rarely behave as if nuclear superiority provides them with advantages in coercive bargaining.”[11] On the other hand, Georgetown University government professor Matthew Kroenig elaborates a “superiority-brinkmanship synthesis” theory that “military nuclear advantages increase a state’s willingness to run risks in international conflicts.”[12] Both arguments are supported with considerable statistical analysis and case studies.

It would seem that, the weaker the connection between nuclear superiority and favorable outcomes in bargaining, the stronger the case for minimum force sizes and capabilities. But in deterrence and in war, the enemy always gets a vote. Therefore any US strategic nuclear posture and supporting arms control regime should continue to include a “hedging” capability for unforeseen challenges and nuclear “black swans.”