Michael May, visionary LLNL director and arms control leader, dies at 100

Michael M. May, the fifth director of Lawrence Livermore National Laboratory (LLNL) and a pioneering physicist who shaped the nation’s nuclear deterrence strategy and arms control policy for more than half a century, died on May 17. He was 100.

A World War II veteran, theoretical physicist, and trusted scientific adviser to multiple U.S. administrations, May’s influence spanned from the earliest thermonuclear design efforts to the evolving security challenges of the 21st century. From advancing weapon design and supercomputing to shaping strategic policy on arms control and nonproliferation, May left a lasting imprint on both the Laboratory and the nation.

“Mike May was a rare combination: a physicist with technical brilliance, a leader with vision, and a strategist with a deep commitment to peace and stability,” said Lab Director Kim Budil. “He helped steer the Lab through a pivotal era and was a cornerstone in shaping today’s scientific contributions to national and international security.”

Early life, war, and the call to physics

Michael Melville May was born on December 23, 1925, in Marseille, France. His father, Jacques May, was a physician and medical geographer whose career in tropical medicine took the family across continents, including years in French Indochina. In 1940, as war engulfed Europe, his mother, Juliette Trarieux May, and the three May children emigrated to the United States, settling in Washington state. Michael was just 14.

In his new home, he quickly adapted. A gifted student, he graduated from Whitman College in Walla Walla at age 18 with degrees in physics and mathematics. He soon joined the U.S. Army during World War II. Spurning an offer to become an officer, he instead elected to serve as a paratrooper in the 101st Airborne Division. He was quickly invited to join a technical group, helping to develop an advanced weapons system. He became a U.S. citizen in 1944. That service marked the beginning of a lifelong understanding of the intersection between science and national security.

After the war, May resumed his academic pursuits, first at the University of Washington and later at the University of California, Berkeley. There, immersed in a thriving community of postwar physicists, he completed a Ph.D. in theoretical physics in 1952.

That same year, newly married and expecting his first child, May received an unexpected invitation from physicist Herb York: “Why don’t you come to Livermore?” May recalled York saying. “We’re opening up a new lab. I can’t tell you what we’re going to be working on, but there will be some very good physicists there.”

May accepted, and on September 8, 1952, he reported for his first day at the brand-new UC Radiation Laboratory in Livermore.

"The first guy I met said ‘I suppose you know we’re working on nuclear weapons?’ " May said. "My jaw dropped."

Describing those early days, May said that the Lab was quite small and informal with considerable research freedom. "It was a startup — that kind of spirit," he said.

Advancing thermonuclear design and computing

May’s early work at Livermore focused on theoretical calculations for thermonuclear weapons. He joined the Lab’s Theoretical Physics Division at a time when the Lab was still defining its mission. Quickly proving himself as an innovative thinker and analytical powerhouse, he became a group leader and later alternate division head under physicist Mark Mills.

May was among the early scientists at the Lab who explored how high-speed computing could revolutionize physics modeling. His pioneering use of computational tools contributed to advances in thermonuclear design and helped strengthen LLNL’s reputation as a technically agile and forward-thinking institution.

By 1962, May had been named associate director for nuclear design, one of the most influential technical roles at the Lab.

LLNL director during a time of transformation

On October 22, 1965, the University of California Board of Regents appointed May director of Lawrence Livermore National Laboratory, succeeding Johnny Foster, who had been tapped by the Pentagon to lead Defense Research and Engineering.

At the time, the Laboratory employed over 5,600 people and was expanding its scientific portfolio beyond weapons into energy, computing, and fusion research. During May’s directorship, the Lab developed warheads for the Poseidon, Minuteman and Spartan missile systems. These designs played a key role in maintaining the United States’ nuclear deterrent posture during the Cold War.

Under his leadership, LLNL acquired its first CDC 7600 supercomputers and expanded magnetic fusion research with experiments such as the Baseball II superconducting magnet. He also supported field experiments under Operation Plowshare, a program that used underground nuclear explosions for peaceful applications such as gas stimulation. Though Plowshare was later phased out, it laid the groundwork for LLNL’s earth sciences and environmental research programs.

In 1971, just before stepping down as director, May initiated the consolidation of the Lab’s various laser research projects, laying the foundation for what would become LLNL’s world-leading laser program. The effort grew rapidly in the next 10 years — from a $2 million budget in 1970 to more than $95 million by 1982.

He was also an early advocate for internally funded research, helping set the stage for programs that would later support scientific innovation across disciplines.

“Leading the Laboratory is the job of many people,” May said, upon resigning from the directorship. “The people at the Laboratory have met exceedingly tough challenges in the past, and they are in a good position to continue to do so in the years ahead. It has been a privilege to work for them as director.”

Leading through complexity

May’s directorship coincided with a tumultuous period in American history marked by the Vietnam War, civil unrest and rising scrutiny of government-sponsored research. Within the Lab, he worked to foster transparency, technical rigor and teamwork. Known for his calm demeanor and thoughtful leadership style, he guided the Lab through challenging conversations about its role in national security while building a culture of excellence.

In later reflections, May credited the Lab’s collaborative spirit as a central strength.

“It was very satisfying to have people here tackle a problem with selflessness and a spirit of teamwork,” May said. “I didn’t create this spirit. It was here before I took the job. But I hope I helped it along.”

Arms control, strategy and continued service

After stepping down as director in 1971, May spent a year as a visiting fellow at the Princeton School of Public and International Affairs (then known as the Woodrow Wilson School of Public and International Affairs). A year later, he returned to Livermore as the Laboratory’s first associate director at large — a role he would hold until his retirement in 1988. 

During this time, he focused increasingly on national security and arms control issues and was often called upon for his far-ranging expertise. In 1974, he served as technical adviser to the U.S. delegation for the Threshold Test Ban Treaty negotiations in Moscow, and from 1974 to 1976, he was a member of the U.S. delegation to the Strategic Arms Limitation Talks (SALT) in Geneva.

He also advised Secretaries of Defense James Schlesinger, Harold Brown, and Caspar Weinberger on missile defense, strategic nuclear balance, and basing options for the MX missile. His analyses and committee work helped shape key decisions during the Cold War.

A long-standing member of the Defense Science Board, May also served on the National Academy of Sciences' Committee on International Security and Arms Control, making several trips to the Soviet Union and China to engage in expert-level dialogue on nuclear risk reduction.

Within LLNL, he led the Laboratory’s Long-Range Planning Committee in the early 1980s to look at the long-term future of the Laboratory and to identify promising new areas of research. As part of that work, he helped launch the Institutional Research and Development (IR&D) program, which provided vital internally funded support for high-risk, high-reward research.

Stanford and global security work

After retiring from LLNL in 1988, May remained an influential contributor to global security conversations. He joined Stanford University as a senior fellow at the Freeman Spogli Institute for International Studies and later co-directed what is today the Center for International Security and Cooperation (CISAC).

At Stanford, May led research on nuclear posture, nonproliferation, terrorism and the role of civilian nuclear energy in national security. In collaboration with scholars and policymakers, he published widely on risk mitigation, policy design and energy futures.

In 2007, he co-hosted a workshop on response planning for a terrorist nuclear detonation in a U.S. city. The resulting report, The Day After, became a reference document for national emergency preparedness planning.

He also chaired a technical working group on nuclear forensics, led workshops on revitalizing the Nuclear Non-Proliferation Treaty, and co-authored a study with Kate Marvel on emerging trends in nuclear energy.

Even into his 90s, May remained an engaged voice in science and policy. His ability to blend technical depth with long-view thinking earned him respect across disciplines and institutions.

Awards and recognition

May’s accomplishments were widely recognized. The Atomic Energy Commission presented him with the Ernest O. Lawrence Memorial Award in 1970. He received the Distinguished Civilian Service Medal in 1975 and the Distinguished Public Service Medal in 1979, both awarded by the Department of Defense. He was a fellow of both the American Association for the Advancement of Science and the American Physical Society. He was also a member of the Council on Foreign Relations, the Pacific Council on International Policy and the International Institute for Strategic Studies.

A legacy of insight and integrity

In 2016, LLNL celebrated May’s 90th birthday with a symposium hosted by the Center for Global Security Research. Former directors, colleagues, and friends gathered to reflect on his legacy. Brad Roberts, director of the Center for Global Security Research, recalled meeting May in the early 1990s.

“He saw the world clearly,” Roberts said. “He spoke compellingly about what mattered and put ideas into play that we still debate today. That’s the kind of mark that Mike May had."

Throughout his life, May remained committed to education. He helped establish the UC Davis Department of Applied Science at Livermore in the early 1960s and taught courses at UC San Diego, Stanford and other institutions. His career was a testament to the belief that scientific inquiry, when paired with thoughtful leadership, can shape a safer and more informed world.

Michael May was preceded in death by his wife, Mary Elizabeth Cottrell, and his sister Bella May. He is survived by his brother, Francis May, and his children Richard, Margaret, Barbara and John, and their families.