Mariano-Florentino Cuéllar

Mariano-Florentino "Tino" Cuéllar is a lawyer, political scientist and former justice of the Supreme Court of California who was president of the Carnegie Endowment for International Peace from November 2021 to June 2026 and in August 2026 became the first chief global affairs officer of Anthropic.¹² He was born in Matamoros, Mexico, and grew up mainly in communities along the U.S.-Mexico border. He graduated from Harvard College and Yale Law School and holds a Ph.D. in political science from Stanford University. He is married to Judge Lucy Koh of the U.S. Court of Appeals for the Ninth Circuit; they have two children.¹

Government and Stanford

Cuéllar began his career at the U.S. Department of the Treasury in Bill Clinton's second term. In the first term of the Barack Obama administration he led the White House Domestic Policy Council's teams on civil and criminal justice, public health, immigration and regulatory reform; he had earlier co-chaired the Obama-Biden transition's immigration working group, and he co-chaired the Department of Education's Equity and Excellence Commission. He has served on the President's Intelligence Advisory Board and the State Department's Foreign Affairs Policy Board.¹

At Stanford he was the Stanley Morrison Professor, with appointments in law, political science and international affairs; he directed the Freeman Spogli Institute for International Studies, co-directed the Center for International Security and Cooperation and led its Honors Program in International Security Studies.¹ Anthropic's announcement adds that he directed the Stanford Cyber Initiative, holds the Cameron Schrier Family Professorship at Stanford Law School, where he "began organizing classes on artificial intelligence nearly a decade ago," and is a senior fellow at Stanford's Institute for Human-Centered Artificial Intelligence.² During nearly seven years on the California Supreme Court, while continuing to teach at Stanford, he wrote opinions on "separation of powers, policing and criminal justice, democracy, technology and privacy, international agreements, and climate and environmental law."¹

He is a member of the American Academy of Arts and Sciences and chairs the board of the William and Flora Hewlett Foundation. He previously chaired the boards of the Center for Advanced Study in the Behavioral Sciences and the Stanford Institute for Innovation in Developing Economies. The National Academy of Sciences appointed him to its Committee on Responsible Computing Research, and he co-chaired the bipartisan Task Force on Nuclear Proliferation and American Security and co-led California's Frontier AI Working Group.¹²

Carnegie Endowment

Cuéllar became president of the endowment in November 2021; William Burns had been its president from 2015 to 2021.¹³ In March 2022 Open Philanthropy recommended 597,717 dollars over two years to the endowment for "a research project on international AI governance led by Matt Sheehan."⁴ When Holden Karnofsky left Open Philanthropy for Carnegie as a visiting scholar on April 29, 2024, he wrote: "Tino Cuellar, Carnegie's President, has been an advocate for taking (what I see as) the biggest risks from AI seriously. Carnegie is looking to increase its attention to AI risk."⁵ Karnofsky, whose wife Daniela Amodei is Anthropic's president, joined Anthropic in January 2025.⁶ Cuéllar's Carnegie biography lists him as a director of Inflection AI, Harvard University and LawZero, and as a trustee of Anthropic's Long-Term Benefit Trust.¹

Anthropic

Cuéllar joined the Long-Term Benefit Trust, the body holding Anthropic's Class T shares and empowered to elect a growing share of its board, in January 2026, when the trustees Kanika Bahl and Zach Robinson left. Richard Fontaine, chief executive of the Center for a New American Security, had joined in May 2025, and Ben Bernanke, former chairman of the Federal Reserve, joined in July 2026.⁷ He left Carnegie in June 2026.¹

On August 4, 2026, Anthropic announced that he would join the company as its first chief global affairs officer, "leading the company's work on policy, strategic international engagement, and government relationships worldwide," and that he had stepped down from the trust, which would select a successor "under its normal process." Cuéllar said: "Democracies must set the terms on which this technology advances, and there is no more consequential place to be shaping that work right now than Anthropic." Daniela Amodei said that he had "spent his career helping public institutions respond to times of change with thoughtfulness, pragmatism, and deep commitment to the common good."²