Dr. SUN Chenghao is a fellow, and head of U.S.-Europe program at Center for International Security and Strategy (CISS), Tsinghua University. His research interests include U.S. domestic and foreign policy, China-U.S. relations, transatlantic relations, AI and International security, etc. He is a member of Munich Young Leaders with Munich Security Conference, visiting scholar at Yale Law School (2024) and fellow at Arms Control Negotiation Academy (2025-2026). Dr. Sun has co-authored dozens of reports and books. His latest books Profound Changes Unseen in a Century and the U.S.-Europe Alliance was published in 2023, and The Gravity of Power in the White House: The National Security Council (1947-2019) in 2020. He is the Top 1% Highly Cited Scholar (2024, 2025) in China according to China National Knowledge Infrastructure (CNKI). Dr. Sun is Council Member of the Chinese Association of American Studies and founder of the Newsletter ChinAffairsplus (www.chinaffairsplus.com).

Research Assistant of U.S.-Europe Program at the Center for International Security and Strategy, Tsinghua University.

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As frontier AI becomes increasingly embedded in cybersecurity, intelligence analysis, military command systems, and critical infrastructure protection, the control of cyber power is no longer exercised solely by states. This paper argues that frontier AI firms are emerging as strategic gatekeepers: they control access to models, compute, cloud infrastructure, safety evaluations, cyber benchmarks, and deployment rules that increasingly shape the distribution and use of cyber capabilities. Recent studies suggest that frontier AI may initially benefit attackers more than defenders in cybersecurity, while also creating new opportunities for automated defense and resilience. This dual-use ambiguity gives private firms unusual authority to decide when capabilities are released, restricted, monitored, or aligned with state security priorities.The paper develops the concept of “privatized strategic gatekeeping” to explain how AI companies mediate between market incentives, national security demands, and international cyber stability. It examines three mechanisms: capability gatekeeping, through model access and cyber-safety testing; infrastructural gatekeeping, through cloud, compute, and platform dependencies; and geopolitical gatekeeping, through firms’ selective alignment with governments, defense agencies, and allied technology blocs. Rather than replacing states, these firms reshape how states exercise cyber power by creating new dependencies and chokepoints.By linking frontier AI governance with debates on digital sovereignty, cyber diplomacy, and strategic stability, the paper contributes to the conference theme of a “digital state of nature.” It shows that the central question is not only how states regulate AI firms, but how these firms increasingly regulate the strategic possibilities available to states.

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