Editor’s Note: This is an excerpt from “Policy Roundtable: The Trump Administration’s Nuclear Posture Review,” from our sister publication, the Texas National Security Review. Be sure to check out the full roundtable.

On May 5, 1962, Secretary of Defense Robert McNamara told his fellow NATO defense ministers that the Kennedy administration was dramatically transforming American nuclear strategy. The United States would move away from Eisenhower’s so-called massive retaliation and instead “engage in a controlled and flexible nuclear response in the event that deterrence should fail.” McNamara told his audience “that nuclear superiority has important meanings” and that “we doubt that the Soviet Union will be able to match this capability.” McNamara also dismissed the “relatively weak nuclear forces with enemy cities as their targets [as] not likely to be adequate to perform the function of deterrence,” a hardly hidden message against the British and French nuclear programs. The new strategy would not only be flexible and controlled, but also focus on building up NATO’s conventional forces. “Surely an alliance with the wealth, talent, and experience that we possess can find a better way to meet this common threat.”

In laying out the flexible response strategy, McNamara presented a bold, radically different plan for the role of nuclear weapons in United States grand strategy. However, almost none of what McNamara said during his Athens speech came to pass under his watch. Fighting a flexible and controlled nuclear war was well beyond American capabilities and the nuclear war plan remained almost completely unchanged during the Kennedy and Johnson administrations. The Soviet Union soon closed the gap in strategic forces with the United States, achieving near parity by the end of the 1960s. The Kennedy administration accepted and even offered to help improve the French and British nuclear programs. In the end, the United States reduced, rather than enhanced, conventional forces assigned to defend Europe. A decade later, President Richard Nixon was recorded saying “Flexible response is baloney.” And in an age of strategic parity, the president declared the “nuclear umbrella in NATO a lot of crap.”

There is always a debate over how much written strategy documents reflect the actual policies and plans of government. The Carnegie International Policy Scholars Consortium and Network, a project hosted by the Kissinger Center, runs an ongoing exercise to assess the purpose and influence of various national security strategies completed in recent years. The program includes several of the authors of these documents, and surprisingly, they rarely agree amongst themselves on the rationale, import, and consequences of the national security strategy. This puzzling disconnect between document and policy is amplified in the Trump administration, where the gap between rhetoric and reality is even wider than in the past. As my colleague Hal Brands has pointed out in assessing the Trump administration’s 2018 National Security Strategy, the document “was not that far removed from what most Republican administrations might have written — only for Trump to give a rabble-rousing, ‘America first’-themed speech that bashed U.S. allies, touted cooperation with adversaries, and raised questions as to whether the president had actually read or even been fully briefed on his own strategy statement.” This trend continues in the release of the Trump administration’s Nuclear Posture Review, which, as James Steinberg observes below, possesses “an Alice in Wonderland” quality.

The typical rhetoric-reality gap in national security is further heightened by the historical strangeness of American nuclear policy. Shortly after the atomic bombing of Hiroshima and Nagaski, the great strategist Bernard Brodie famously explained: “Thus far the chief purpose of our military establishment has been to win wars. From now on its chief purpose must be to avert them.” While there has been and remains great controversy and disagreement over how to achieve this aim, few doubt that the primary goal of nuclear strategy is to make sure nuclear weapons are never delivered and detonated. At the same time, however, the United States has had great ambitions in the world since 1945, and has often assigned nuclear weapons an oversized role in achieving those aims. It seeks not only to deter adversaries from attacking the American homeland (a relatively easy task), but also from attacking its many far-flung friends and allies around the world. It also expects these friends to remain non-nuclear, while hoping its adversaries remain deterred without fear of an American first strike or the launch of a costly arms race. The goals the United States is attempting to achieve with its nuclear weapons — deterrence, assurance, inhibition, and reassurance, and the qualities upon which they depend, namely, credibility and resolve — are almost impossible to observe or measure.

The Nuclear Posture Review and critiques of the document, as well as most statements about the nature of nuclear weapons and their influence on international politics, are often based on little more than guesswork. As Janne Nolan and Brian Radzinsky trenchantly observe in this roundtable:

Nuclear planning is made difficult because of the lack of strong evidence about how the character and composition of American nuclear forces affect the behavior of others. In the absence of such clarity, decision makers and experts tend to fall back on their worldviews and beliefs about the nature of international politics.

Despite — or perhaps because of — the elusive nature of nuclear strategy, we must combine rigor and humility in our analysis. The reason for rigor is obvious: Nuclear war would be catastrophic. Short of nuclear war, many of the aims of American grand strategy rely upon effective nuclear policies. The modernization of nuclear systems called for in the review — which builds upon plans laid out by the Obama administration — would be expensive (over a trillion dollars over thirty years), resources that could be allocated to other military programs. Many of these upgrades focus on capabilities — stealth, speed, miniaturization, lower-yields, dual-use — that some see as destabilizing. America’s nuclear policy will also be watched by other countries, nuclear and non-nuclear, and will help shape those countries’ own decisions in an unfolding, uncertain world order. The stakes surrounding American nuclear policy are, therefore, enormous.

Except when they are not. What role has American nuclear strategy played in the most consequential issues in U.S. national security policy in recent decades, such as the wars in the Balkans, Iraq and Afghanistan, counter-terrorism, globalization, and even the re-balance to Asia? And if nuclear strategy did matter, how would we know? Imagine a radical counterfactual where the United States suddenly possessed no nuclear weapons — what would happen to the United States tomorrow? In five years? In fifty? We can all speculate, and we should, as long as we recognize that the answers we offer are speculations and not scientifically proven rules. This is where humility must come into play. We spend extraordinary resources on weapons we hope will never be used, and we can never be certain we are going about it in the right way. Nolan and Radzinsky’s excellent description of nuclear posture reviews could be applied to many arguments about nuclear weapons and their consequences: They are like “party platforms,” containing well-intentioned aspirations as well as many inherent contradictions. The cleavages that exist in the nuclear debate reflect differences in the inherent worldviews and strategic beliefs rather than any fundamental “differences in core values or priorities.” We are stumbling through the dark.

All six of these excellent reviews combine rigor with humility while disagreeing in productive ways. Each has its own take on the Nuclear Posture Review and focuses on different aspects of the document. Five issues in particular are worth highlighting:

1. Continuity versus change: Students of the history of American foreign relations recognize that there tends to be more continuity across different administrations and political parties, as well as over time, that we often recognize in real-time. The Trump administration, with its pointed rhetoric and the president’s rhetorical attack on sacred tenets of the bipartisan foreign policy consensus, appears to represent a dramatic break from past policies and practices. But is it? Analysts are divided. Austin Long sees the Trump Nuclear Posture Review as “fundamentally undermining many of the assumptions underlying the 2010 Nuclear Posture Review,” while Steinberg sees it as, “in many respects,” a “radical departure.” Others are less sure. As Al Mauroni points out, the 2010 and 2018 reviews “have more in common than not.” Rebecca Herseman captured this nicely when she pointed out that Trump’s review “had something in it for everyone” which meant that “almost no one is happy.
2. Usability, discrimination, and low yields: One of the ironies of nuclear deterrence is that its effectiveness depends upon willingness to actually use nuclear weapons. There is a real reason to doubt the United States would respond to anything short of a nuclear attack on the American homeland with its strategic nuclear forces. To improve the credibility of extended deterrence and assurance promises to allies in this situation, some suggest that developing weapons and strategies that lower the threshold for nuclear use is in America’s interest. This generates its own challenges. Given the United States’ extraordinary non-nuclear capabilities, why would it want to lower the nuclear threshold and emphasize nuclear weapons? What’s more, blurring the lines between strategic, sub-strategic, and conventional (dual-use) capabilities could lead to dangerous miscalculations in a crisis. Vipin Narang suggests that, “In trying to deter more — and lower — forms of aggression with nuclear weapons and broaden the deterrence spectrum, the Nuclear Posture Review generates real risks of spirals of nuclear escalation in a crisis or war.”
3. What are the Russians up to? As Long points out, “the Nuclear Posture Review is concerned about Russia,” both its menacing geopolitical behavior and its own nuclear modernization and altered nuclear strategy. In particular, there is a concern about its so-called “escalate to de-escalate” strategy, in which Russia would use a nuclear weapon at the sub-strategic level, based on the calculation that the United States could not credibly respond with strategic level nuclear weapons. Does the review get Russia — its intentions, strategies, and capabilities — right? According to Kristin Ven Bruusgaard, “The new Nuclear Posture Review will neither slow down nor change Russian military developments or its behavior in future conflicts.” A larger question is whether the United States should craft its nuclear policies to respond to a vexing but declining state whose remaining power rests in no small part on its nuclear weapons.
4. Using nuclear threats to deter non-nuclear actions. The United States has always reserved the right to use nuclear weapons to deter or respond to a devastating non-nuclear attack, such as a Warsaw Pact blitzkrieg through the Fulda Gap during the Cold War or a biological or chemical weapons attack in more recent years. The Nuclear Posture Review appears to expand the scenarios in which nuclear weapons can be employed to a debilitating cyber-attack. As Steinberg points out, this expansion of deterrence generates further questions concerning the credibility of deterrence, as well as encouraging others like Russia or China to embrace the same policy, to the potential detriment of American interests. The United States already asks more of its nuclear policies than any other country; is it wise to expand their writ?
5. Extended deterrence and assurance: Nuclear weapons are often described as insurance against invasion and conquest. The United States, however, has not been threatened with invasion and conquest since the end of the Civil War, if then. Nor would it be vulnerable to such a threat even if it were to get rid of all its nuclear weapons tomorrow (just as the risk of invasion would not have been any higher in 1975 or 1955 if the United States had been without the bomb at that time). What makes America’s nuclear policy so challenging is that, unlike other nuclear states, it tries to do far more with these weapons than simply prevent an invasion and conquest of its homeland. Namely, it seeks to protect a wide array of states around the world from attack while discouraging these same clients (and others) from acquiring their own invasion insurance.

It would not take much — far less than is called for in this or previous American nuclear postures — to deter a nuclear attack on the United States. This Nuclear Posture Review, like the reviews and strategies that have come before it, is driven and shaped by the costs and dilemmas associated with achieving extended deterrence, assurance, and inhibition. It is easy to forget, from a historical perspective, how ambitious America’s nuclear strategies have been for decades. We can debate whether these policies have been wise or not. On the one hand, America’s nuclear postures have been extraordinarily expensive and arguably exposed the United States (and the world) to much danger. On the other hand, the United States prevailed in the Cold War, far fewer states have independent nuclear weapons than anyone could have imagined seventy, fifty, or even twenty-five years ago, interstate conflict has declined and great power war has all but disappeared. What is the connection between these fortuitous outcomes and America’s robust and forward leaning nuclear postures? The truth is, the question is both extraordinarily important and almost impossible to answer with any certainty.

It is no surprise that there is much disagreement over the import of the Trump administration’s Nuclear Posture Review. In the end, however, it is important to recognize that documents like this one have often had less connection and consequence to what actually matters in the making of policy — especially nuclear policy — than we believe. At the end of the day, the nature of our political system provides the president of the United States with enormous independent authority to use nuclear weapons if and when he or she chooses. What little we know of how past presidents thought about this extraordinary responsibility indicates that that responsibility left them awe-struck, shaken and committed to making sure they were never faced with the horrific decision to use these weapons; even Nixon was “appalled” after his first briefing on the Single Integrated Operational Plan. Literally nothing matters more than how a president thinks about and acts on this sacred responsibility, and literally nothing should worry us more in our current circumstances.

Francis J. Gavin is the Chairman of the Editorial Board of the Texas National Security Review.  He is the Giovanni Agnelli Distinguished Professor and the inaugural director of the Henry A. Kissinger Center for Global Affairs at SAIS-Johns Hopkins University. His writings include Gold, Dollars, and Power: The Politics of International Monetary Relations, 1958-1971 (University of North Carolina Press, 2004) and Nuclear Statecraft: History and Strategy in America’s Atomic Age (Cornell University Press, 2012).  

Image: U.S. Air Force