Since 2019, the Brookings Institution and the Center for International Security and Strategy at Tsinghua University (Tsinghua CISS) have convened teams of national security technology experts from the United States and China for an unofficial Track-II dialogue on artificial intelligence (AI) in national security. The two teams identified a need to build parallel glossaries of AI terms—one developed by U.S. experts and the other developed by Chinese experts—to enable a precise understanding of each other’s intended meanings when discussing AI and national security.

What follows is a glossary of terms that play a meaningful role in the application of AI to matters of international security, stability, and military affairs. The definitions for each term were compiled and reviewed by the U.S. experts involved in the Brookings-Tsinghua CISS dialogue. Where possible and appropriate in the view of the scholars, the definitions draw from government publications—however, in no case are definitions offered as official or authoritative. As technology, state doctrine, and practice evolve, these definitions will require further elaboration, and official policy will supersede these interim definitions. This glossary—and the parallel Chinese companion glossary—are released in the spirit of attempting, on the basis of mutual interest, to provide greater clarity on this critical issue. As this dialogue advances, both sides will aim to add relevant terms to the glossary.