ABSTRACT

This chapter explores the causes and consequences of the propensity among US intelligence agencies to overpredict the spread of nuclear weapons in the world. It proceeds in five steps. The first section defines proliferation and highlights five characteristics of nuclear politics and technology that make predicting states’ proliferation behaviour particularly challenging. The second section describes the accuracy of US intelligence estimates of global proliferation trends. To explain how the analysts overpredicted proliferation, the third section musters evidence showing an unwarranted focus of US intelligence on capabilities, which often favours overestimates. The fourth section shows how ominous predictions informed crucial US policy initiatives that reinvigorated the nonproliferation regime. The last section puts the US track record of overprediction into perspective.