Nuclear Deterrence and Nuclear Strategy
In the study of nuclear strategy, my scholarship revolve around the central questions of the nuclear age: Would any leader ever choose to begin a nuclear war? If not, then why do nuclear weapons have as much influence on statecraft as they do? My work therefore tracks the strength and perception of a norm against the use of nuclear weapons among elites, historically and today. It also revises how the field thinks about nuclear risk, its perception and management.
One major answer in the field to the puzzle of nuclear credibility is called the strategy of “brinkmanship.” It argues that nuclear weapons have political effects not through traditional means of credible signaling per se but instead through the variable of risk—that states can demonstrate that they are willing to run a greater risk of nuclear war than the other side. Having been set aside after the Cold War, the concept of “brinkmanship” is back in foreign policy debates. Revisionist powers are testing the scope for crises and limited war under the nuclear shadow, from Taiwan to Ukraine and from South Asia to the Korean Peninsula. But my field’s dominant theory of brinkmanship is empirically questionable. Leaders rarely manipulate risk during crises in a manner predicted by Thomas Schelling’s “threat that leaves something to chance.” We therefore need to know more precisely how nuclear-armed states resolve intense disputes without going to war. This is the topic of my second book, Nuclear Brinkmanship: Manipulating and Managing Risk in International Crises.
I co-authored an article critiquing the literature on brinkmanship with insights from the study of human psychology: “The Psychology of Nuclear Brinkmanship,” International Security (with Rose McDermott). Schelling’s “threat that leaves something to chance” resolved the problem of nuclear credibility by removing the human being, making escalation not a matter of choice; but bringing in scholarship from psychology preserves a role for humans. Chance and choice coexist, because “chance” in a nuclear crisis can come from the possibility that a stressed, emotional, bias-prone leader will make a choice that rational models rule out. Colleagues and I applied the framework to understand the escalation potential of the war in Ukraine: “Putin and the Psychology of Nuclear Brinkmanship” Foreign Affairs (with Rose McDermott and Paul Slovic).
Another way that I have approached the central questions of nuclear strategy and credibility is to think about barriers to the use of nuclear weapons, such as deterrence, traditions, or taboos. In International Security, I published “Would U.S. Leaders Push the Button?: Wargames and the Sources of Nuclear Restraint.” It evaluates the relative prominence of non-use arguments—deterrence, practicality, precedent-setting, reputation, and ethics—in elite wargames played during the Cold War. I have long been interested in elite discourse on nuclear norms, including the intellectual history of key figures in U.S. nuclear policy grappling with the emergence of a non-use norm. My article, “Bedeviled by a Paradox: Nitze, Bundy, and an Incipient Nuclear Norm,” The Nonproliferation Review, won the McElvany Nonproliferation Challenge from the James Martin Center for Nonproliferation Studies.
This research agenda has led me to the study of “second-order beliefs” about nuclear weapons. With Lee-Or Ankori-Karlinsky and Daniel Post, I investigate the sources of norm-following behavior and distinguish between those who act on intrinsic beliefs about appropriate behavior and those who follow norms because of their perception about others’ beliefs. Our first working paper fielded two survey experiments with a U.S. public sample and with an elite sample of U.S. military personnel. Our second working paper uses evidence from archival wargames to identify what audiences U.S. policymakers invoked when considering the simulated use of nuclear weapons, and how often they made arguments based on first- versus second-order beliefs. Together these works pursue a perceptual turn in the study of norms and gather evidence about what decision-makers actually believe. If norms operate through second-order beliefs—what one thinks others think—then those beliefs can be systematically right or wrong. Norms are therefore more than just “strong” or “weak,” they can also be “hollow” or “hidden”.