In the final episode of The Nuclear Threshold, A’ndre speaks with Alexandra Bell, President & CEO of the Bulletin of the Atomic Scientists and one of the leading U.S. diplomats behind recent efforts to strengthen arms control and reduce nuclear risks. Building on the technical and command-and-control foundations laid by Laura Grego and Steve Fetter, this conversation shifts to the political and diplomatic fault lines that make today’s nuclear landscape uniquely dangerous.

Alexandra explains why nuclear policy has fallen out of public view even as the world edges closer to crisis, and why diplomacy — often undervalued and underfunded — remains the only real mechanism for preventing disaster. Drawing on her experience negotiating the New START Treaty and other engagements, she breaks down the collapse of Cold War–era treaties, the rise of new nuclear states, and the challenge of rebuilding trust in a multipolar world.

We also explore how deterrence theory holds up in an era of political volatility and weapons on minutes-notice alert. Alexandra discusses realistic steps the United States and others could take to reduce tensions, the role of scientific cooperation when politics freeze, and why public engagement has always been the catalyst for major progress on nuclear issues.

As the Doomsday Clock sits closer to midnight than ever, Alexandra makes the case for “fearless diplomacy” — and why, despite the risks, the path away from catastrophe is still possible if governments and citizens choose it.