Ever since the United States dropped atomic bombs on Hiroshima and Nagasaki, no nuclear weapons have been used in combat. This limits all efforts to develop theories about nuclear strategy, as does the fact that serious nuclear crises have been few and far between. Those who worry that something will go badly wrong one day can point to some close calls but no catastrophes. The Cuban missile crisis looms large in all such discussions, yet that confrontation was the product of a particular set of circumstances and of the approaches adopted by the main protagonists, U.S. President John F. Kennedy and Soviet Premier Nikita Khrushchev. In his study of nuclear superiority, Kroenig notes that both men thought that the appearance of having greater strength mattered. As evidence, he points to how the public’s belief in the “missile gap”—the claim that the Soviet Union had more and better missiles than the United States—influenced the two countries’ politics and policies, even though, in the end, the assertion proved false.
Kroenig uses Kennedy’s and Khrushchev’s convictions to himself argue that superiority always matters. He challenges the orthodox view that once a state has a second-strike capability—and so can assure the destruction of any country that launches a first strike against it—more bombs and missiles are superfluous. He proposes that superiority allows leaders to run greater risks during crises, something he sees as a positive. If a nuclear exchange begins, he argues, leaders who can escalate further and faster than their opponents will be able to limit the damage. Kroenig carries out some quantitative analysis with the modest amount of data available and offers a few brief case studies, although it is not clear that the Sino-Soviet crisis of 1969 (during which the Soviet Union considered launching a preventive nuclear war against China) fits Kroenig’s model, as China barely had an operational nuclear arsenal at that time. Kroenig draws attention to the reasons why policymakers desire superiority, but his book fails to show that it is really the nuclear balance that makes the difference in crises, as opposed to the balance of conventional forces or countries’ differing stakes in the outcome.
Cohen looks at some of the same cases in greater detail and draws a different conclusion. He points not so much to the raw numbers of bombs and missiles but to the chance that a new leader may be overoptimistic about capabilities and so act too assertively. At first, this tendency can prompt confrontations, he argues, but the experience of getting close to the brink dampens leaders’ enthusiasm for future risk-taking. Cohen analyzes how politicians learn from and adapt after crises and demonstrates just how sobering the prospect of war can be. But much still depends on individual personalities, and, as Cohen notes, the learning experience has to be repeated with each new generation of leaders.
The importance of personalities comes across in Ambinder’s riveting account of nuclear tensions in the early years of the Reagan administration. At the heart of the story lies Soviet paranoia that the United States might launch a surprise first strike, a fear that reached its height in 1983, when nato carried out an exercise known as Able Archer, which simulated a nuclear conflict. The Soviets feared that the exercise was a cover for the real thing. Ambinder focuses on concerns both countries held about the integrity of their nuclear command-and-control arrangements. U.S. policymakers were particularly preoccupied with the question of who would be in charge of nuclear decision-making if the president and the vice president were both killed (a problem that was underlined by the attempted assassination of U.S. President Ronald Reagan in 1981). Ambinder paints a sympathetic portrait of Reagan, who was seized with deep forebodings about a nuclear Armageddon. Reagan was surprised to learn how much the United States scared the old men in the Kremlin. But once he understood their fears, he sought to ease tensions.
The vulnerability of command-and-control systems will only grow in importance with the development of cyber-capabilities, which will present new opportunities for interference. Malicious actors might launch weapons by mimicking authorization codes or triggering warning systems, or they might use cyberattacks to prevent legitimate launches. Even without outside attacks, the excessive complexity of nuclear weapons systems can lead to errors and accidents. There are already some sobering examples: attempts to compromise conventional radar and air defense systems, a commander’s personal computer being taken over to send false messages during a military exercise, nuclear facilities that lost communications because of equipment failure, and hackers trying to break into messages between nuclear submarines and onshore forces. Futter’s valuable book surveys the new dangers and also considers how states might deter cyberattacks on critical infrastructure. He stresses the importance of securing sensitive nuclear information and of keeping control systems as simple as possible and separating them from other networks.