At the end of the Cold War, the United States and Russia entered into agreements to reduce the numbers of nuclear weapons in their arsenals. The excess-weapons plutonium recovered from dismantled weapons is extremely toxic in the environment, and the National Academy of Sciences has characterized the possibility that it could fall into the hands of terrorists as a “clear and present danger.” A team of operations research analysts supported the Office of Fissile Materials Disposition (OFMD) in the US Department of Energy (DOE) by developing a multiattribute utility (MAU) model to evaluate alternatives for the disposition of the excess-weapons plutonium. Russian scientists modified the model with the aid of the US team and used it to evaluate Russia's disposition alternatives.