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 urgentaction to reduce the risk. Some terrorist groups are activelyseeking nuclear weapons and the materials to make them; it isplausible that a technically sophisticated terrorist group couldmake a crude nuclear bomb if it acquired enough highly enricheduranium (HEU) or plutonium; important weaknesses innuclear security still exist in many countries and thefts of HEUand plutonium have already occurred; nuclear smuggling is verydifficult to interdict; and the consequences of a terrorist nucleardetonation would be immense and far-reaching. Nuclear thievescould strike in any country. In this article, we outline a baselineset of adversary capabilities that all stocks of nuclear weapons,plutonium, or HEU should be protected against, no matter whatcountry they are in, including both insiders and outsiders and arange of potential tactics. We recommend that countries facingmore substantial adversary threats put even more capable securitysystems in place. The article calls for international cooperationCountries facing more capable adversaries should provide protectiongoing beyond the baseline level we describe. The article callsfor international cooperation, including technical and financialassistance where needed, to ensure that at least this baseline levelof protection is in place for all nuclear weapons, plutonium, andHEU worldwide.