On April 8, researchers, students, and policy experts from around the world tuned in to a Princeton virtual seminar to discuss whether the world’s most destructive weapons are becoming easier to use.
The seminar, one of many hosted by Princeton’s Program on Science and Global Security (SGS), featured Lisa Langdon Koch, a political scientist and professor at Claremont McKenna College. Koch’s 2023 book, “Nuclear Decisions: Changing the Course of Nuclear Weapons Programs,” examined leaders’ decisions around nuclear development. Koch identifies three distinct “proliferation eras,” in which changing political environments have either constrained or accelerated nuclear weapons development.
For SGS, the seminar was a small piece in the much larger story of nuclear security scholarship at Princeton.
Founded in 1974 by Princeton physicists, SGS is “one of the oldest and most highly regarded academic programs focused on technical and policy studies on nuclear issues in the world.” The program, based in Princeton’s School of Public and International Affairs (SPIA), has spent the past five decades working to ensure that scientific voices informing government decisions on nuclear issues are not beholden to government or corporate interests.
“The government has scientists, the corporations have scientists,” Zia Mian, a co-director of SGS, said in an interview with The Daily Princetonian. “The public needs scientists — and they need to be independent.”
That philosophy, which Mian calls “public interest science,” has deep roots at Princeton, particularly on nuclear issues.
In 1939, while living in Princeton and working at the Institute for Advanced Study, Albert Einstein co-wrote the Einstein-Szilard letter to President Franklin Roosevelt, which warned that nuclear fission could be weaponized and urged the U.S. to begin its own research.
Seven years later, Einstein founded one of the world’s first nuclear-awareness organizations, the Emergency Committee of the Atomic Scientists, at 90 Nassau Street — just a few hundred feet from Nassau Hall. Einstein wrote fundraising letters warning that nuclear weapons could destroy civilization. He also sponsored the first documentary film on nuclear weapons and mobilized religious groups, labor unions, and women’s organizations in what Mian described as “hardcore activism.”
Mian notes that SGS sees itself as the heir to the tradition of nuclear disarmament advocacy. “Physicists invented these things,” Mian said, referring to nuclear weapons and the field of nuclear warfare. “Without the physicist, this thing does not work. So we have a relationship to [the field].”
That sense of responsibility has brought SGS into international policymaking. Mian and other members of the program helped develop the humanitarian framework behind the 2017 United Nations (UN) Treaty on the Prohibition of Nuclear Weapons, with 99 countries becoming states parties or signatories to the Treaty as of September 2025. Mian currently serves as co-chair of the Treaty’s Scientific Advisory Group, briefing diplomats from nearly 100 nations on nuclear risk and consequences.
One of the advisory group’s early moves was advising the UN to commission the first global study in 40 years on the potential effects of nuclear war. In December 2024, the UN General Assembly voted to launch the study. They wanted people to at least “just agree [on] what [nuclear war] would look like, Mian said. “If the temperature rises more than one and a half degrees, the climate really becomes a big problem for everyone,” Mian said. “By four degrees, it’s a complete catastrophe. We want a similar understanding about nuclear war,” she added..”
Through its lobbying efforts, SGS also helped convince Congress to commission a 2025 National Academy of Sciences study on nuclear winter, the phenomenon where smoke from fires caused by large-scale nuclear war rises into the stratosphere, blocks sunlight worldwide, and triggers agricultural collapse.
In an interview with the ‘Prince,’ SGS co-director Alexander Glaser noted that arms control progress unfolds over years and decades so that researchers are “ready when there’s an opportunity to actually make a difference.” He described ongoing work to develop “virtual inspection” protocols for arms control verification and ensuring that the SGS is ready with proposals to present when needed.
“There will be a time when the relations with Russia and China hopefully will get better again,” Glaser said. “And you want to be in a position to say, ‘We have some proposals and some ideas that we can share.’”
This long-term orientation extends to the program’s graduate researchers. Raven Witherspoon GS, an SGS Ph.D. student, has shifted her focus from international non-proliferation to the domestic risks of nuclear weapons — specifically, communities living near facilities where weapons are maintained, stored, and refurbished. Her work draws on hotspot modeling, atmospheric data, open-source weather information, and geospatial mapping. Right now, Witherspoon is “more on the technical side in order to try to understand what communities might be impacted by health concerns.”
The program’s current research spans several fronts: tracking global stockpiles of the uranium and plutonium used in nuclear weapons through the International Panel on Fissile Materials, examining how commercial satellites can be used to verify arms control compliance in the absence of treaties, and studying the implications of a potential U.S. space-based missile shield. SGS also recently accepted its first doctoral student researching AI and autonomous weapons, tackling modern advancements in technology.
Raven said that rising geopolitical tensions do not change her day-to-day research, but do impact the public’s reaction to these events. She noted that when global fears arise, public attention moves toward immediate international flashpoints and away from the long-term domestic nuclear risks she studies, leaving her to navigate between the two spaces. “It does fuel me to be in both worlds at the same time,” she said.
She also wants to raise SGS’s profile on campus, pointing to an ongoing film series and the Princeton Nuclear Action group as efforts to connect the program to the broader University community. “Most people could not tell you what SGS stands for,” she said. “SGS is a beautiful thing to be a part of … My personal goal is integration with SGS and the rest of the Princeton community.”
For Mian, Koch’s seminar reflects that same broader mission: treating nuclear weapons not only as a technical or diplomatic problem, but as a public one.
“To have a debate about nuclear weapons and nuclear war today, let’s all at least first have an agreed understanding of what nuclear war would look like,” he said.
Daphne Lewis is a staff News writer for the ‘Prince.’ She is from Washington, D.C. and can be reached at dl1424[at]princeton.edu.
Please send any corrections to corrections[at]dailyprincetonian.com.