Post-Explosion Nuclear Attribution and Deterrence by Michael Miller A thesis submitted to the Center for International Security and Cooperation Undergraduate Honors Program Stanford University May 24, 2006 Advisor: Michael May, Professor of Management Science and Engineering, Emeritus Second Reader: Siegfried Hecker, Visiting Professor Post-Explosion Nuclear Attribution and Deterrence by Michael Miller Abstract Nuclear attribution or post-explosion forensics is the process of determining the origin of nuclear material after a nuclear incident. While nuclear terrorism has been well-explored in academic literature, there are no technical assessments of attribution capability. This thesis attempts to fill that gap by combining an assessment of the current technology with the contribution that attribution can make toward deterrence. I find that the technology behind attribution is well-developed but not foolproof, and I conclude that if the current capabilities were publicized more thoroughly and the post-explosion process of assessing the evidence were internationalized, states and individual actors might be deterred more than they already are. I explore other possible policy options, including a nuclear database and nuclear tagging, and these are found to be useful but to add less to deterrence. May 24, 2006 iii Acknowledgements This thesis, my endeavor for the year, would not have been possible without guidance and help from numerous sources along the way. First, and most importantly, I’d like to thank my advisor, Michael May, who has helped me tremendously from the day I came by his office when he knew nothing about me and thought my first topic was a bit crazy. By generously signing on to be my advisor and then helping guide my research throughout, always with an eye toward the larger goal of what I was trying to accomplish, he has set the model that I will try to emulate throughout my career. Sig Hecker has also been incredibly helpful with his insights into how these nuclear processes actually work and into what all the subjects of my thesis, from the North Koreans to the Russians, really think. I could not have asked for two better or more thorough advisors, and I want to truly thank them. A number of people at CISAC have guided me through the honors program, and they deserve acknowledgement for their advice and frequent helpful comments. Scott Sagan, Tino Cuellar, Paul Kapur, and Dara Cohen helped me shape the direction of my thesis, from its rough outline to a more ambitious and even more impossible idea. They oddly decided to object when I proposed studying shadowy terrorist networks but not when I proposed studying an even more secret government program with no record trail or scholarly history. And they only blinked a few times when, in my first presentation, I noted that the most interesting aspects of nuclear attribution were “unknown and unknowable.” With much encouragement from them and even more from my classmates, I discovered quite a lot exploring a field where I felt that I could genuinely contribute to public knowledge. The rest of the CISAC community has also been instrumental in welcoming me and the rest of the undergraduates for the year. Jonathan Farley, Dave Hafemeister, and Lynn Eden all went out of there way to include me. Most importantly, I’d like to thank Stephen Stedman for teaching the best class I took at Stanford, my first quarter freshman year (where I also did the most work), and for introducing me to the honors program. Outside of CISAC, I received instrumental help from John Harvey, who first suggested the topic of nuclear attribution and later met with and helped my finalize the approach of relating deterrence to attribution. Jay Davis was also generous, meeting me v in his home to discuss attribution and giving me a sense of what the true expert thought. Finally, this thesis never would have gotten started or finished without the total support of my girlfriend, Andrea Burbank, who gave up much of her time to keep me on track and even found time between assignments to proof the whole final copy. I couldn’t wish for a better muse. And my parents and brother been supportive throughout the year, and they deserve great thanks for giving me such a wonderful opportunity. Michael Miller May 23, 2006 [email protected] vi Table of Contents CHAPTER 1: INTRODUCTION .......................................................................................................1 Literature Review ....................................................................................................................6 Methodology ............................................................................................................................9 CHAPTER 2: THE TECHNOLOGY OF ATTRIBUTION ....................................................................11 History...................................................................................................................................12 First steps: nuclear spying ....................................................................................................13 Tracing nuclear forensics ......................................................................................................17 Current technical capabilities................................................................................................20 Questions and methods for a post-explosion nuclear attribution..........................................26 CHAPTER 3: DETERRENCE .........................................................................................................31 Defining deterrence in context ..............................................................................................32 Rational deterrence theory—does it apply to asymmetric situations?..................................34 Can terrorists be deterred? ....................................................................................................36 Where nuclear attribution fits...............................................................................................38 Former Soviet Union: ............................................................................................................43 North Korea ...........................................................................................................................46 Pakistan .................................................................................................................................48 Research Reactors ..................................................................................................................50 Putting the deterrence together .............................................................................................51 CHAPTER 4: ATTRIBUTION AS DETERRENCE .............................................................................53 Stopping a clandestine deal ...................................................................................................53 Credibility of retribution .......................................................................................................57 Improving weapons security—a negligence doctrine? .........................................................62 Deterring terrorists from using nuclear weapons with attribution......................................64 CHAPTER 5: CONCLUSION AND POLICY RECOMMENDATION ...................................................69 A database..............................................................................................................................71 Nuclear tagging.....................................................................................................................75 Revealing more information ..................................................................................................77 International collaboration ....................................................................................................79 A guaranteed retaliation........................................................................................................80 Maintaining the status quo ...................................................................................................82 Conclusion.............................................................................................................................83 MICHAEL MILLER Chapter 1: Introduction Sometimes fiction can be an excellent window into reality. In Tom Clancy’s The Sum of All Fears, Islamic terrorists detonate a nuclear device in Denver.1 They obtain the weapons material on the black market (it was originally taken from a downed Israeli aircraft) and use bribed Russian nuclear scientists to construct a bomb. They smuggle it to the United States and place it in a vending machine at the Super Bowl. All these steps, while individually difficult, are extremely feasible. If terrorists can acquire nuclear material—by far the most difficult step in the supply chain—they can probably find the technical skills to build and detonate a nuclear weapon. Graham Allison argues for this feasibility in his summary book, Nuclear Terrorism, and the picture he paints of weapons of mass destruction exploding in cities around the globe is haunting. Despite its dark premise, Clancy’s novel ends on a positive note. Nuclear forensics teams arrive on the site quickly and take debris samples that they compare against a database of nuclear reactors. Within minutes they trace the radioactivity to a U.S. reactor that had supplied fuel