Although nuclear weapons have played a critical role in American defense strategy for more than 60 years, there is a growing debate over the number and type of nuclear forces that the United States actually needs to maintain its security and protect its allies. Over the past several years, calls for Washington to substantially reduce the size of its nuclear arsenal have become more prevalent, while the combination of declining budgets and looming recapitalization costs have made nuclear weapons a popular target for potential funding cuts. 

Proposals to significantly reduce or even abolish nuclear weapons are as old as nuclear weapons themselves. Over the past several years, however, they have gained considerable momentum and moved squarely into the mainstream of policy analysis and political debate.

As the Pentagon nears completion of its ongoing Strategic Choices and Management Review, the Center for Strategic and Budgetary Assessments conducted an external Strategic Choices Exercise with teams of experts from three other prominent think-tanks—CSIS, AEI and CNAS–to inform public debate.

DoD faces a fundamental choice in how it prepares to trim its budget under such a high degree of uncertainty. It can change the way it does business or change the business it does. Under the deepest cuts proposed, it may well need to do both.

On April 6, the Department of Defense released its Nuclear Posture Review (NPR), which sets forth the Obama Administration’s guidance on American nuclear policy, force structure, and doctrine. The report has been highly anticipated, due in large part to President Obama’s public commitment to the goal of a nuclear weapons-free world.

Over the past several years, the prospect of a terrorist group armed with a nuclear weapon has frequently been cited as a genuine and overriding threat to the security of the United States. Moreover, press reports indicate that the forthcoming Nuclear posture review will make the goal of countering nuclear terrorism “equal to the traditional mission of deterring a strike by major powers or emerging nuclear adversaries.”1 Although the likelihood of a nuclear terrorist attack may be relatively low, the consequences of such an attack would obviously be enormous. There is, therefore, widespread agreement regarding the severity of this threat. Despite this consensus, a number of important questions remain open to debate: How real is the risk that a terrorist group could acquire or construct a functional nuclear device, and how might it attempt to do so? Which group poses the greatest threat in this regard, how has that threat changed over time, and is it currently growing or abating? What existing and prospective measures will prove most effective in preventing terrorists from obtaining a nuclear weapon, stopping them from delivering and detonating a weapon if prevention fails, and responding both at home and abroad in the event that an attack succeeds? The purpose of this backgrounder is to examine these critical issues.