“One cannot fashion a credible deterrent out of an incredible action” — Robert McNamara. The concept of nuclear deterrence gained increased prominence during the Cold War period when a generation of national security scholars and practitioners, including Bernard Brodie, Kenneth Waltz, etc., advocated nuclear development as an effective deterrent. However, most academic research on the subject is directed towards explaining the theoretical modalities of nuclear deterrence rather than a systematic analysis of the empirical evidence on the efficacy of nuclear weapons as a deterrent. In the 21st century, the growing efforts to stigmatise and ultimately ban nuclear weapons reflect a shift in the nuclear weapons debate — a shift that aims at challenging the long-held myth of nuclear deterrence. Conventional wisdom suggests that the strategy of nuclear deterrence is always successful and prevented many cold war crises from erupting into full-scale nuclear war. The advocates of this theory are of the view that the overwhelming fear of mutually assured destruction provides a measure of stability in times of crisis. In their opinion, nuclear deterrence provides full security against attacks with conventional forces or nuclear weapons, thus reducing the likelihood of war between two nuclear-armed countries to a minimum. This argument gained such widespread acceptance that it today emerges as a formidable obstacle in the way of efforts to promote nuclear disarmament. These advocates of nuclear optimism are so assertive in their view that their influence in both academia and policy-making circles can easily be seen. More importantly though, powerful lobbies in almost all nuclear weapon states have developed stakes in vast nuclear establishments, spending budgets of billions of dollars. These vested interests always resist efforts to cut down nuclear weapons. In 2010, President Obama had to earmark $ 185 billion to modernise nuclear warheads and delivery systems over the next 10 years in the bargain for smooth passage of the new Strategic Arms Reduction Treaty (START) with Russia. The trump argument in favour of retaining nuclear weapons capability is that the use of nuclear weapons brought an early end to World War II. New research by a well-known Japanese historian, Tsuyoshi Hasegawa, has proved it totally wrong that Japan surrendered because of the dropping of atomic bombs on Nagasaki and Hiroshima. In fact, the Japanese decided to surrender when the Soviet Union renounced the 1941 Neutrality Pact and joined the Allied Powers in war. By 1944, 66 Japanese cities had been completely destroyed by conventional weapons but the Japanese government continued military resistance — the destruction of two more cities could not make much difference. History is witness to the fact that attacks aimed at ordinary civilians are rarely given any consideration when it comes to taking vital decisions in times of war. After the end of World War II, Japan’s leaders attributed their failure to the sudden use of nuclear weapons only because it was politically convenient for them on the domestic front to blame an ‘outside’ factor. Ward Wilson, a famous nuclear expert and director of the Rethinking Nuclear Weapons Project, is of the view that nuclear deterrence is an unsound basis for the national security policy because it is neither as effective at political persuasion nor as capable of influencing military conflicts as many proponents of nuclear weapons would have us believe. For total reliance on the nuclear deterrence strategy it has to be prefect but historical records show that deterrence could work only in a few cases. Even a single case of failure has the potential to lead to a nuclear war. More alarmingly, deterrence threats, due to their inherently uncertain nature, sometimes lead enemy nations to behave in ways that are quite inimical to achieving the goal of deterring aggression. During the early years of the Cold War, nuclear proponents would claim that the presence of nuclear weapons had enormous potential to ensure success in political negotiations while preventing all sorts of conventional or nuclear attacks. However, an impartial analysis of political events during the Cold War calls the fundamental soundness of these claims into question. It is part of the historical record that the possession of nuclear capability by the US could not intimidate the Russians during talks after World War II. The Yom Kippur War of 1973 proved the second part of the argument wrong that nuclear weapons could prevent any sort of attack. Israeli nuclear capability could not prevent a number of Muslim states from starting an all-out war for regaining occupied territory and for Palestinian independence. The efficacy of the nuclear umbrella was also questioned when the UK and France developed their own nuclear capability despite concrete assurances of security from the US. As French President Charles de Gaulle famously said, the US would not trade New York for Hamburg. The Cuban missile crisis is another case often cited to support the idea of nuclear deterrence. It is generally believed that the nuclear deterrent was the main factor that brought back the US and Soviet Union from the brink of a nuclear war during the Cuban missile crisis. When the information regarding the installation of nuclear-armed Soviet missiles in Cuba became known, though US President Kennedy knew that by blockading Cuba he would touch off a crisis that could lead to nuclear war, he went ahead, undeterred. The fact of the matter is that the Soviet Union’s decision to withdraw nuclear missiles may be regarded as supporting the nuclear deterrence theory but Kennedy’s reaction does not support the theory. In 2008, Michael Dobbs, a British politician, wrote an insightful book titled One Minute to Midnight, revealing that the Cuban missile crisis came very close to a nuclear war at least three separate times during those decisive days and nuclear war was averted not by the efficient functioning of nuclear deterrence, but just ‘by chance’. In a nutshell, the idea of nuclear deterrence is too fragile to be relied upon and the fear of massive nuclear retaliation is not always able to prevent countries from taking the course of action they want. Ward Wilson and a number of other nuclear experts have frequently claimed in their works that the “failure rate of nuclear deterrence is potentially higher than theory admits”. The emerging threat of nuclear terrorism is also a question mark on the efficacy of nuclear deterrence because terrorist groups hardly take well thought out rational decisions, as states are believed to take. The continued existence of nuclear weapons is also the reason for their gradual spread. So long as even one country has nuclear capability, others will also want to acquire that status. The writer is a research scholar and a former visiting fellow at the Monterey Institute of International Studies, California. He can be reached at rizwanasghar7@hotmail.com)