A study conducted by University of Wisconsin–Madison and Princeton University nuclear engineers has identified a major blind spot in nuclear accounting with global nuclear security implications. According to the researchers, large quantities of uranium have been extracted, concentrated and exported from the Democratic Republic of the Congo (DRC) over the past 20 years. This uranium has traveled …
A map depicting the areas in North America at risk of receiving high levels of radioactive fallout based on simulations of nuclear attacks on silos for each day of 2021. Map by Sébastien Philippe, Ivan Stepanov and Svitlana Lavrenciuc Wisconsin may not be the economic, political or military center of the United States. But the state …
As nuclear agreements end and talk of nuclear weapons testing builds, the U.S. is entering a new era of nuclear policy, says Sébastien Philippe. “There won’t be agreements stopping countries from a nuclear arms race,” he says. “We often think nuclear weapons policies are the realms of experts and the military, but in fact, everybody …
Photo of Sébastien Philippe. Credit: John D. and Catherine T. MacArthur Foundation. Sébastien Philippe, a visiting researcher at the Princeton School of Public and International Affairs’ Program on Science & Global Security (SGS), has been awarded a 2025 MacArthur Fellowship. Philippe’s achievement puts him among 20 scientists, artists, and scholars across the country who will …
Nuclear security specialist Sébastien Philippe, an assistant professor at the University of Wisconsin–Madison, has been awarded a 2025 MacArthur Fellowship. Often referred to as “genius grants,” the fellowships are presented by the John D. and Catherine T. MacArthur Foundation to individuals based on their exceptional creativity, dedication to their pursuits and the potential for their work to benefit …
On September 5, 2025, Assistant Professor Sébastien Philippe participated in the first meeting of the Independent Scientific Panel on the Effects of Nuclear War, a new initiative launched by the United Nations. Announced by UN Secretary-General António Guterres on July 17, 2025, the panel will examine the possible physical effects and societal consequences of nuclear war. The last …
Early in his academic career, Sébastien Philippe realized the potential for his work to have a major societal impact. His research on the consequences of French nuclear weapon testing in the South Pacific led to him co-authoring the book Toxique, published in 2021. Using hundreds of declassified French government documents, on-the-ground interviews in France and in Polynesia, and countless …
New Town, N.D., has 14 ballistic missile silos within a 20-mile radius. It is on the Fort Berthold Indian Reservation, home of the Mandan, Hidatsa and Arikara Nation. Nina Berman This article is part of “The New Nuclear Age,” a special report on a $1.5-trillion effort to remake the American nuclear arsenal. Last March the …
The Mandan, Hidatsa and Arikara peoples are learning more about the missiles siloed on their lands, and that knowledge has put the preservation of their culture and heritage in even starker relief. Written by: Ella Weber Edited by: Sébastien Philippe, Jeffery DelViscio & Tulika Bose
This research advances methods for inspecting high‑risk, adversary‑controlled sites, addressing a central technical challenge in nuclear verification and arms control.