Office of Defense Nuclear Nonproliferation

NNSA's Office of Defense Nuclear Nonproliferation (DNN) is America's shield against nuclear and radiological attack. DNN stops threats before they can reach the U.S. Homeland through a multi-layered defense: - **Deny** adversary access to weapons-usable material, technology, and expertise; - **Detect** nuclear proliferation and breakouts; and - **Defeat** efforts by adversaries to attack or threaten the U.S. homeland with the world's most dangerous weapons. DNN is critical to deterring nuclear and radiological attacks against the United States. U.S. strategic deterrence starts with the world's most robust, credible, and modern nuclear weapons stockpile. But it does not end there. To achieve deterrence, DNN and its partner agencies must also deny, detect, and defeat efforts by rogue states and terrorists to acquire nuclear or radiological weapons, as well as efforts by existing nuclear-armed adversaries to improve their arsenals and threaten the United States. In executing its national security mission, DNN carefully tailors its projects so that they also enable American Energy Dominance. DNN partners with America's nuclear industry to advance nonproliferation and commercial goals at every step of the deployment process; from the design of nuclear reactors, to the high-assay low-enriched uranium used to fuel them, to the agreements for nuclear cooperation that prepare their export. In turn, a strong and healthy U.S. commercial nuclear industry enhances national security and is a force multiplier for DNN's work around the world. - Read more about the office's work in DNN's [annual report to Congress](https://www.energy.gov/nnsa/articles/prevent-counter-and-respond-nnsas-plan-reduce-global-nuclear-threats-npcr) and the [DNN Sentinel newsletter](https://www.energy.gov/nnsa/nnsas-dnn-sentinel). - Learn about opportunities for U.S. companies to partner with DNN at the [Nuclear Nexus](https://www.energy.gov/nnsa/nuclear-nexus) web platform.