Against a background of serious international tensions, triggered by Russia’s invasion of Ukraine in February 2022, the role of nuclear deterrence is back on the agenda, with Vladimir Putin in particular talking about the use of nuclear weapons. In this book (Pax Atomica: Theory, Practice and Limits of Deterrence) Bruno Tertrais, deputy director of the Foundation for Strategic Research, explains the principles of nuclear deterrence and asks the question: can the atomic bomb prevent serious conflicts?
Nuclear weapons were only used in the bombings of Hiroshima and Nagasaki in August 1945 (after a successful test in New Mexico in July 1945), followed by Japan’s surrender.[1] Today, nine states — the United States, Russia, China, the United Kingdom, France, Israel, India, Pakistan and North Korea — use deterrence in different ways, with the author listing seven, ranging from general and immediate deterrence to indirect deterrence (threats aimed at a state’s allies). In his first chapter, he reminds us that deterrence, particularly nuclear one, is a psychological process: the use of a serious threat against a potential adversary, who is assumed to be capable of rationality in order to measure the extent of the damage to which he is exposing himself. It is more of an art than a science, and “more akin to a game of poker than a game of chess”. It is based on credible means (weapons, delivery systems, intelligence and command resources) and on a stated intention to use them, but with a calculated vagueness so that the adversary cannot assess the damage he is exposing himself to.
The author devotes three of the ten or so chapters to the operational translation of deterrence and its dilemmas. Deterrence has three objectives: to protect its own territory from a major non-nuclear attack, to prevent the use of nuclear weapons by an adversary in a conflict, and to protect its nuclear forces against a surprise attack. It must avoid an uncontrolled escalation, as the use of nuclear weapons as a simple instrument of combat is no longer envisaged. There are two opposing schools of thought. The first one gives priority to manipulating the risk, often associated with the idea of mutually assured destruction, while the second envisages having a diversified arsenal of offensive and defensive weapons, the stability of deterrence being difficult to achieve. There are two types of weapons: atomic bombs, which are simpler and hydrogen bombs, which are more complex and use thermonuclear fusion (the tritium in the bomb being not stable). Increasing the precision of these weapons means that less powerful ones might be used (megat...
