All Stocks of Weapons-Usable Nuclear Materials Worldwide Must be Protected Against Global Terrorist Threats

The danger of nuclear terrorism is real enough to justify urgent action to reduce the risk. Some terrorist groups are actively seeking nuclear weapons and the materials to make them; it is plausible that a technically sophisticated terrorist group could make a crude nuclear bomb if it acquired enough highly enriched uranium (HEU) or plutonium; important weaknesses in nuclear security still exist in many countries and thefts of HEU and plutonium have already occurred; nuclear smuggling is very difficult to interdict; and the consequences of a terrorist nuclear detonation would be immense and far-reaching. Nuclear thieves could strike in any country. In this article, we outline a baseline set of adversary capabilities that all stocks of nuclear weapons, plutonium, or HEU should be protected against, no matter what country they are in, including both insiders and outsiders and a range of potential tactics. We recommend that countries facing more substantial adversary threats put even more capable security systems in place. The article calls for international cooperation Countries facing more capable adversaries should provide protection going beyond the baseline level we describe. The article calls for international cooperation, including technical and financial assistance where needed, to ensure that at least this baseline level of protection is in place for all nuclear weapons, plutonium, and HEU worldwide.