The Case for U.S. Nuclear Weapons in the 21st Century

The Case for Nuclear Weapons in the 21st Century Stanford University Press


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This book is a counter to the conventional wisdom that the United States can and should do more to reduce both the role of nuclear weapons in its security strategies and the number of nuclear weapons in its arsenal.  That conventional wisdom, argues Brad Roberts in The Case for Nuclear Weapons in the 21st Century, has not been informed by the experience of the United States since the Cold War in trying to adapt deterrence to a changed world or of the Obama administration to create the conditions that would allow further significant changes to U.S. nuclear policy and posture.  A CISAC affiliate, Roberts served as Deputy Assistant Secretary of Defense for Nuclear and Missile Defense Policy during the first Obama administration. He wrote the book, which draws heavily on his experience in government, during his time as a consulting professor and William J. Perry fellow at CISAC in 2014. To purchase the book, please visit:

Why did you write this book?

My main purpose was to reclaim the middle in the U.S. nuclear policy debate.  As in so much of the rest of our national political life, the middle has disappeared from this particular debate, leaving two deeply antagonistic camps to dominate it. One favors more disarmament now, while the other sees many enduring roles for U.S. nuclear weapons. The division didn’t matter so long as the United States could live off the investments of the Cold War.  It can no longer do so, as old weapons and delivery systems age out and expensive decisions must be made.  A coherent and centrist approach is needed to guide national choices, and this book attempts to fill that gap.


What is your main argument?

That the conditions do not now exist for the United States to safely take additional steps to further reduce the number and role of U.S. nuclear weapons. The Obama administration set out a strategy for creating those conditions in 2009, and the results have been disappointing. Russia has rejected further arms control. China has rejected further transparency.  Others have refused to join an international consensus against nuclear weapons. This experience must temper enthusiasm for the disarmament project. The conditions do not exist and are not proximate.


What is the case against nuclear weapons? And why do you think the case for nuclear weapons is more compelling?

The case against nuclear weapons has been made on many grounds:  historical (‘these are nothing more than cold war relics’), moral (‘their use in war would violate the laws of war so deterrence is immoral as well’), and prudential (‘we can’t prove that deterrence works but we can prove that these are dangerous weapons’). The case for nuclear weapons derives first and foremost from the role the United States wants to play in the world—as a security guarantor to others and a projector of power to promote stability and our values. In today’s world, without nuclear weapons, the United States could not play that role.


Can you ever imagine a scenario where the U.S. would need to use nuclear weapons again?

We don't have nuclear weapons to fight and win wars with them; we have nuclear weapons to ensure they are never used against us or our allies—in other words, for deterrence.  The President would only consider the employment of nuclear weapons in extreme circumstances when the vital interests of the United States or an ally are at risk. Though extreme, such circumstances are not implausible. The cold-war vintage bolt-from-the-blue major strike isn’t the potential problem today; rather, the problem is a regional conflict that goes badly for an adversary who then tries to escalate his way out of failed aggression against a U.S. ally. At least three nuclear-armed potential adversaries have now long studied the common problem they face:  deterring and defeating a conventionally-superior nuclear-armed major power and its allies. They have developed theories of victory built around nuclear coercion, blackmail, and brinksmanship, aimed at breaking the will of the United States and its allies, including with limited nuclear strikes to demonstrate their resolve. Our deterrence strategy requires that we have an effective ability to respond and that the threat to employ it in the circumstances they create is credible. Moreover, let us distinguish the verb “employ” from “use.” U.S. nuclear weapons are used every day to cast a shadow of doubt over the thinking of potential challengers to U.S. interests and to assure our allies. 


President Obama set out a vision for a world free of nuclear weapons at a speech in Prague in April, 2009. Does your book contradict the President’s strategic vision?

President Obama is a pragmatist and this was reflected in the Prague speech. In 2009, we took some steps to reduce the role and number of nuclear weapons and set out a plan for working with others to create the conditions for further reductions. But so long as nuclear weapons remain, the President is committed to ensuring that nuclear deterrence remains effective. Toward that end, the administration has expended considerable time, energy, and money.  This is the story of that effort and a distillation of key lessons.