Nuclear security around the world has improved dramatically over the last three decades—which demonstrates that with focused leadership, major progress is possible. But important weaknesses remain, and the evolution of the threat remains unpredictable. The danger that terrorists could get and use a nuclear bomb, or sabotage a major nuclear facility, or spread dangerous radioactive material in a “dirty bomb,” remains too high. The United States and countries around the world need to join together and provide the leadership and resources needed to put global nuclear security on a sustained path of continuous improvement, in the never-ending search for excellence in performance.

The 2016 nuclear security summit was a pivotal moment for the decades-long effort to secure nuclear material around the globe. More than 50 national leaders gathered in Washington for the last of four biennial meetings that have led to significant progress in strengthening measures to reduce the risk of nuclear theft.

"Today and tomorrow, world leaders will gather for what will likely be the final international summit on security for nuclear weapons and the materials needed to make them—a key tool for preventing nuclear terrorism. The last time this group met, at the 2014 Nuclear Security Summit in the Hague, they declared that preventing terrorists from acquiring nuclear weapons or weapons-usable materials remained “one of the most important challenges in the years to come.” Yet, since then, nuclear security has improved only marginally, while the capabilities of some terrorist groups, particularly the Islamic State, have grown dramatically, suggesting that in the net, the risk of nuclear terrorism may be higher than it was two years ago..."

In this new report, Preventing Nuclear Terrorism: Continuous Improvement or Dangerous Decline?, Matthew Bunn, Martin Malin, Nickolas Roth, and William Tobey provide a global reality check on nuclear security. They note that effective and sustainable nuclear security capable of addressing plausible threats is the single most effective chokepoint preventing terrorists from acquiring a nuclear weapon.

In the lead-up to the nuclear security summit, Advancing Nuclear Security: Evaluating Progress and Setting New Goals outlines what was accomplished in a four-year effort launched in 2009 to secure nuclear material around the globe—and what remains to be done. The effort made significant progress, but some weapons-usable nuclear materials still remain “dangerously vulnerable." The authors highlight the continuing danger of nuclear and radiological terrorism and call for urgent action.

This chapter assesses whether terrorists are actually seeking nuclear weapons; whether a terrorist organization could, if it had the needed nuclear materials, be capable of building a nuclear bomb; whether terrorist organizations could plausibly get the needed nuclear materials; and what the consequences of a terrorist nuclear attack might be. The chapter then describes the substantial progress made in reducing the risk of nuclear theft in recent years and the gaps that still remain. Finally, the chapter offers suggestions for strengthening nuclear security for the long haul.