with HEU, and more than 120 civil research reactors and associated facilities around the world with 20 kg or more of HEU.¹⁰¹

The threat of HEU leakage is not hypothetical, even if, to the best of our knowledge, acquisition by those with proliferation aspirations thankfully remains so for now. For example, as recently as 2006, 100 grams of stolen HEU of approximately 90 percent enrichment was recovered in the Republic of Georgia. The material was suspected to have originated in Russia, but efforts to identify its provenance were unsuccessful, and Georgian authorities were reportedly dissatisfied with the degree of cooperation they received from Russia.¹⁰² This seizure is not an isolated incident; an International Atomic Energy Agency (IAEA) database includes 17 separate incidents between 1993 and 2001 involving illicit trade in HEU or plutonium, with quantities as large as several kilograms, although the sum of the material intercepted during this period was inadequate for a nuclear bomb.¹⁰³ To underscore the point further, in 2006 the U.S. National Intelligence Council assessed that “Undetected smuggling of weapons-usable nuclear material has likely occurred, and we are concerned about the total amount of material that could have been diverted or stolen in the last 15 years. We find it highly unlikely that Russian or other authorities would have been able to recover all the material likely stolen.”¹⁰⁴

Eliminating civil HEU by 2015 is also feasible. Efforts to address elements of the civil HEU threat date back almost as far as the spread of this material beginning mid-century. For example, both the United States and Russia have long had in place programs to accept the return of HEU they supplied to other states. But until recently these efforts were ad hoc and addressed only a small fraction of potentially vulnerable materials.

New opportunities following the end of the Cold War led to additional activity, including some high-profile U.S.-initiated efforts to remove material stockpiles of particular concern. In recent years this activity has coalesced into a more systematic effort, involving the United States, Russia, and the IAEA, to identify, secure, and remove potentially vulnerable HEU stockpiles. The United States has taken the initiative on this issue and plays a key ongoing role in carrying out operations. Russia has played an important cooperative role, providing logistical and technical capabilities and taking back Soviet-origin material for disposition. Finally, the IAEA has increasingly played an essential role as a coordinator, knowledge base, and contracting mechanism that also brings with it a degree of international legitimacy absent from purely bilateral or trilateral efforts.

Although the goal is both desirable and feasible, it is also ambitious, and a variety of specific steps must be taken now and in the coming years if it is to be realized. Important progress has already been made, ensuring that at least some of these materials will never fall into the wrong hands. At the same time, much more remains to be done. There is substantial room to