Frank von Hippel is one of the United States’ most prominent scientists in the nuclear policy arena. He co-founded Princeton University’s Program on Science and Global Security and the International Panel on Fissile Materials, and is a member of the Bulletin‘s Board of Sponsors. A former assistant director for national security in the White House Office of Science and Technology, von Hippel’s policy research currently focuses on reducing global stocks of weapon-usable fissile materials and the number of locations where they can be found. Most recently, he has been the coauthor of the book Plutonium: How Nuclear Power’s Dream Fuel Became a Nightmare (Springer, 2019) and the report Banning Plutonium Separation (International Panel on Fissile Materials, 2022).