Michael A. Levi and Micah Zenko say nuclear terrorism, however unlikely, is one of the few prospects that could truly devastate the USA, and there are still steps that the U.S. can take to reduce the odds of a catastrophic attack.

The United States has made real strides against nuclear terrorism, but efforts to secure nuclear materials are incomplete and will require continued commitment, says CFR's Michael Levi.

Analysts Paul K. Kerr and Mary Beth Nikitin of the Congressional Research Service discuss the extent to which ongoing instability in Pakistan has called recent nuclear weapons-related reforms into question.

CFR’s Michael A. Levi and Harvard’s Graham T. Allison consider the likelihood of catastrophic nuclear terrorism in the United States.

Michael Levi speaks with cfr.org's Eben Kaplan about the consequences of nuclear terrorism on U.S. soil.

Preventing Catastrophic Nuclear Terrorism makes clear what is needed to reduce the possibility of nuclear terrorism. It identifies where efforts have fallen short in securing and eliminating nuclear weapons and weapons-usable nuclear materials, and it offers realistic recommendations to plug these gaps in the U.S. and international response.

The threat of a nuclear attack—especially a nuclear detonation—by terrorists has never been greater. The United States and the international community must do more to prevent terrorists from buying, stealing, or building nuclear weapons. This report identifies where efforts have fallen short in securing and eliminating nuclear weapons and weapons-usable nuclear materials, and it offers realistic recommendations to plug these gaps in the U.S. and international response.

A profile of the chemical agent mustard gas.