"An ambitious but anxious China, a confrontational Russia, some regional powers, such as Iran, and more capable non-state actors are challenging longstanding rules of the international system as well as U.S. primacy within it," the agencies said in the 2024 Annual Threat Assessment of the U.S. intelligence committee.

(Reporting by Patricia Zengerle, Jonathan Landay and Michael Martina; Editing by Leslie Adler)