Nuclear leakage from the Newly Independent States of the former Soviet Union is an ongoing national security concern of the United States. While little weapons-usable material and no nuclear warheads have surfaced in international smuggling channels, observed data from seizures and arrests are not necessarily representative of the wider universe of illegal nuclear deals. Political and economic upheavals and associated nuclear security problems in Russia in the 1990s accentuated the risk of serious proliferation episodes. Adversaries such as Iran and Al Qaeda have tried to exploit these vulnerabilities to further their nuclear ambitions, although with uncertain results. Improved intelligence collection on the nuclear black market—who the players are, what items they seek, how they plan to obtain them and how successful they have been—should complement the essentially reactive and stationary risk management systems now in place in Russia and elsewhere.