US Nuclear Strategy: Theories, Metaphors, and Scenarios

In world politics, everything is interconnected. The United States' nuclear strategy will have increasingly serious implications not only for US national security, but also for assorted allies, most notably Israel. Opinion

The Ohio-class ballistic missile submarine USS Maryland (US Navy photo by Mass Communication Specialist 1st Class James Kimber)

Going forward, a core question arises: What particular explanatory frameworks can best guide the Trump administration in its vital nuclear dealings with North Korea and Iran? In partial response, US strategists should operate according to the basic assumption of enemy rationality. These planners must also prepare for scenarios that would involve non-rational judgments or even outright enemy madness.

Rationality, Irrationality and Madness

Details are needed. In strategic studies, decisional irrationality does not mean the same as madness. Residual warnings about madness, however, could still merit serious policy consideration. This is because "ordinary" irrationality and full-scale madness could both have comparable and consequential effects upon a country's national security decision-making.

Any country.

Words matter. In normal strategic parlance, "irrationality" identifies a decisional orientation or modality wherein national self-preservation is not the highest preference. Significantly, a prospectively irrational decision-maker in Pyongyang or Tehran need not be "mad" in order to become a problem for designated leaders in Washington. Such an adversary needs only to be more expressly concerned about certain other preferences or values than collective self-preservation.

While this sort of preference ordering may sound implausible in Washington, it ought to sound much more comprehensible or to-be-expected in Jerusalem and Tel Aviv. In Israel, after all, such ranked priorities are recognized and dealt with daily among assorted Jihadist foes, Sunni and Shia.

To determine whether a particular adversary should be deemed irrational or "mad," US military planners would first have to input a generally similar decisional calculation. Here, the underlying premise must be that a pertinent adversary might not be suitably deterred from launching a military attack by any American threats of retaliatory destruction, even where such threats would be fully credible and expectedly massive. Such a prospective failure of US military deterrence could include both conventional and nuclear retaliatory threats.

In fashioning America's nuclear strategy vis-à-vis both nuclear and not-yet-nuclear adversaries, US military planners must include a mechanism to determine whether a conspicuous adversary (e.g., North Korea or Iran) will more likely be rational or irrational. In operational terms, this means ascertaining whether the relevant foe will value its collective survival (either as a state or as an organized terror group) more highly than any other preference or combination of preferences. This early judgment must always be based upon defensibly sound analytic principles; they should never be affected merely by what the analysts might themselves "want to believe."

Pretended Irrationality, Escalation Dominance and Dialectical Thinking

A corollary US obligation, depending in large part upon this prior judgment concerning enemy rationality, will expect strategic planners to assess whether a posture of "pretended irrationality" could sometime enhance America's nuclear deterrence posture.  On several occasions, it should be recalled, President Donald Trump openly praised at least the underlying premises of such an idiosyncratic posture.

US enemies include state and sub-state foes, singly and also in various forms of collaboration. Such forms could be "hybridized" in different ways between state and sub-state adversaries. In dealing with Washington, each recognizable class of enemies could itself sometime choose to feign irrationality. In principle, this could represent a potentially clever strategy to "get a jump" on the United States in any expected or already-ongoing competition for "escalation dominance."

Any such calculated pretense could fail, perhaps even calamitously.

On occasion, these same enemies could "decide," either consciously or unwittingly, to be irrational.  In such bewildering circumstances, it could become incumbent upon American strategic planners to capably assess which particular form of irrationality – pretended or authentic – is actually underway. These planners would then need to respond with a dialectically orchestrated and optimally counterpoised set of useful reactions.

The term "dialectically" (drawn originally from ancient Greek thought, especially Plato's dialogues) is used here with very precisely stipulated meanings. This is to signify a continuous or ongoing question-and-answer format of inherently complex strategic reasoning.

By definition, any instance of enemy irrationality would value certain specific preferences (e.g., presumed religious obligations or personal and/or regime safety) more highly than collective survival. For America, and also for its Israeli ally, the grievously threatening prospect of some irrational nuclear adversary is prospectively most worrisome with regard to North Korea and at least possibly in the rapidly closing future, Iran. Apropos of such more-or-less credible apprehensions, it is unlikely that they could be meaningfully reduced by way of formal treaties or agreements.

Here it is well worth remembering seventeenth-century English philosopher Thomas Hobbes' classic warning in Leviathan: "Covenants, without the sword, are but words...."

Preemption Options, National Security and Asymmetrical Military Power

How should the United States proceed? At some point, the best option could seem to be some sort of preemption; that is, a defensive non-nuclear first-strike directed against situationally appropriate hard targets. Yet, it is already very late for launching any operationally cost-effective preemption against North Korea, and – even if it could be properly defended in law as "anticipatory self-defense" – such action would come at a too substantial cost.

In specific regard to current and potentially protracted US-Iran enmity, the American side must carefully consider how, if at all possible, its nuclear weapons could be usefully leveraged against that Islamic Republic in identifiable war scenarios. A rational answer could never include any actual use of such extraordinarily destructive weapons. Rather, the only pertinent questions for US planners should concern the calculable extent to which an asymmetrical US threat of nuclear escalation could (if deemed necessary) be rendered credible.

By definition, as long as Iran were to remain non-nuclear, any US nuclear threat would be asymmetrical.

By applying all available standards of ordinary reason and logic (there are, after all, no appropriate historical points of reference in such literally unprecedented situations), Washington could best determine that certain nuclear threats against Iran would serve American and Israeli security interests only when Iranian military capacities (though still non-nuclear) were sufficiently overwhelming. Such a scenario, though perhaps difficult to imagine, might nonetheless be conceivable. This is especially the case if Tehran were ever able to escalate (a) to massive direct conventional attacks upon American territories or populations, and/or (b) to the use of biological warfare capabilities.

Derivatively, in view of the very close relationship between Washington and Jerusalem, such nuclear threats against Iran might also make sense if Tehran were ever to consider launching massive conventional and/or biological attacks upon Israel directly.

All this should now imply a primary obligation for the United States (c) to focus continuously on steady incremental enhancements to its implicit nuclear deterrence posture; and (d) to develop a wide and nuanced range of possible nuclear retaliatory options. The specific rationale of (d) above, would be a counter-intuitive understanding that the credibility of nuclear threats could sometime vary inversely with perceived levels of destructiveness. In a calculation that could apply to Israeli decision-makers as well as to their American counterparts, this means that the successful nuclear deterrence of a non-nuclear Iran could depend upon nuclear weapons that were deemed sufficiently low-yield or small.

Washington should also continue to bear in mind any US nuclear posture's imperative focus on prevention rather than punishment. In absolutely any and all circumstances, using America's own available nuclear forces for vengeance instead of deterrence would miss the principal point – which, invariably, is to optimize US national security. Accordingly, any American nuclear weapons use based on narrowly corrosive notions of revenge, even only as a residual default option, would be not only purposeless, but irrational.

America's nuclear deterrent must always be backed up by recognizably robust systems of active defense (BMD), especially if there should be any determinable reason to fear an irrational nuclear adversary. Although it is well-known that no system of active defense can ever be entirely "leak-proof" (a point that is already widely recognized in Israel, even after the considerable successes of Arrow, Iron Dome and David's Sling) there is still good reason to suppose that BMD deployments could help safeguard both US civilian populations (soft targets) and American nuclear retaliatory forces (hard targets). This means, inter alia, that technologically advanced anti-missile systems must remain indefinitely (as in the derivative case of Israel) a steadily-modernizing component of America's nuclear deterrence posture.

Offense, Defense and US Nuclear Deterrence

It must be borne in mind that in the nuclear age, seemingly defensive strategies could be viewed by variously uneasy adversaries as offensive. This is because the secure foundation of any system of nuclear deterrence must be some reasonable presumption of mutual vulnerability.

"Everything is very simple in war," says Clausewitz, in On War, "but the simplest thing is still difficult."

To progress in its most vital national security obligations, American military planners must more expressly identify the prioritized goals of their country's nuclear deterrence posture. Before any rational adversary could be suitably deterred by an American nuclear deterrent, that enemy would first need to believe that Washington had capably maintained the capacity to launch appropriate nuclear reprisals for relevant forms of aggression (nuclear and perhaps even non-nuclear), and the requisite will needed to undertake such a consequential firing.

About the first belief criterion, it would almost certainly lie "beyond any reasonable doubt."

The second belief expectation, however, could prove problematic and thus "fatally" undermine US nuclear deterrence

In more perplexing matters involving an expectedly irrational nuclear enemy, successful US deterrence would need to be based upon distinctly credible threats to enemy values other than national survival.

The United States may also need to demonstrate, among other things, the substantial invulnerability of its own nuclear retaliatory forces to any enemy first strike aggressions. More precisely, it will remain in America's long-term survival interests to continue to emphasize its assorted submarine-basing nuclear options. Otherwise, as is reasonable to contemplate, even America's land-based strategic nuclear forces could potentially present to a strongly-determined existential enemy as somehow "too-vulnerable."

For the moment, of course, this is not a significantly serious concern, though Washington will want to stay focused on the planned deployment of submarines by its Israeli ally in the Middle East. The point of any such focus should be on strengthening Israeli nuclear deterrence, which – in one way or another – would be to the overall strategic benefit of the United States.

"Deliberate Nuclear Ambiguity" or Disclosure

Looking ahead, America will have to rely increasingly on a multi-faceted doctrine of nuclear deterrence. In turn, like its already-nuclear Israeli ally, specific elements of this "simple but difficult" doctrine could need to be rendered less "ambiguous." This complex and finely nuanced modification will imply an even more determined focus on prospectively rational and irrational enemies, including both national and sub-national foes.

To deal most successfully with its presumptively irrational or non-rational enemies, the US will need to compose an original strategic "playbook." Here, once again, it could become necessary for Washington to consider, at least on occasion, feigning irrationality. In such cases it would be vitally important for the American president not to react in any ad hoc or "seat-of-the-pants" fashion to each and every new strategic challenge or eruption, but instead to derive or extrapolate specific policy reactions from a suitably pre-fashioned strategic nuclear doctrine.

Without such a thoughtful doctrine as guide, pretended irrationality could become a "double-edged sword," effectively bringing more rather than less grievous security harms to the United States.

There is one penultimate but still critical observation. It is improbable, but not inconceivable, that certain of America's principal enemies would be neither rational nor irrational, but mad. While irrational decision-makers would already pose special problems for US nuclear deterrence – by definition, because these decision-makers would not value collective survival more highly than any other preference or combination of preferences – they might still be made susceptible to various alternate forms of deterrence.

For example, resembling rational decision-makers, they could still maintain a fixed, determinable and "transitive" hierarchy of preferences.

This means, at least in principle, that "merely" irrational enemies could still be successfully deterred.

Mad or "crazy" adversaries, on the other hand, would have no such calculable hierarchy of preferences, and would therefore not be subject to any identified strategy of American nuclear deterrence. Although it would likely be far worse for the United States (or Israel) to have to face a mad nuclear enemy than a "merely" irrational one, Washington (or Jerusalem) would have no foreseeable choice in this matter. The US, like it or not, will need to maintain, perhaps indefinitely, a "three track" system of nuclear deterrence and defense, one track for each of its adversaries that is presumptively (1) rational (2) irrational  or (3) mad.

For the notably unpredictable third track, special plans will be needed for undertaking certain potentially indispensable preemptions, and, simultaneously, corresponding/overlapping efforts at ballistic missile defense.

Naturally, there could be no assurances that one "track" would always present exclusively of the others. This means, significantly, that American decision-makers could sometimes have to face deeply intersecting or interpenetrating tracks and that these complicated simultaneities could even be synergistic.

There is one genuinely final observation. Even if America's military planners could reassuringly assume that enemy leaderships were fully rational, this would say nothing about the accuracy of the information actually used by these foes in making calculations. Always, it must never be forgotten, rationality refers only to the intention of maximizing certain designated preference or values.

It says nothing about whether the information being used is either correct or incorrect.

Prudence, Humility and America's Nuclear Strategy

Fully rational enemy leaderships could still commit serious errors in calculation that lead them toward a nuclear confrontation or a nuclear war. There are also some related command and control issues that could impel a perfectly rational adversary or combination of adversaries (both state and sub-state) to embark upon various risky nuclear behaviors. It follows, prima facie, that even pleasingly "optimistic" assessments of enemy leadership decision-making could never reliably preclude authentically catastrophic outcomes.

For the United States, understanding that no scientifically accurate judgments of probability can ever be made about unique events (by definition, any nuclear exchange would be sui generis or precisely such a unique event), the best lessons for America's president should favor a determined prudence and a very deliberate humility. Of special interest, in this connection, is the erroneous presumption that having greater nuclear military power than an adversary is automatically an assurance of bargaining success.

This is because the tangible amount of deliverable nuclear firepower required for deterrence is necessarily less than what could ever be required for "victory."

For the United States, classical Greek warnings about hubris, left unheeded, could elicit once unimaginable spasms of "retribution." None of this suggestion is meant to exaggerate America's reasonable nuclear fears or apprehensions, but only to remind that competent national security planning must remain a determinedly intellectual effort, a persistently complex struggle of "mind over mind." Whether for Washington or for Jerusalem, or both, it ought never be considered an easily calculable contest of "mind over matter."


Louis René Beres, a frequent contributor to IsraelDefense, is Emeritus Professor of International Law at Purdue. He lectures and publishes widely on matters of Israeli security and nuclear strategy.

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