Pentagon's Top Policy Chief to Resign After NATO Summit.

Colin Kahl, the Pentagon's top policymaker, plans to resign and return to the private sector, likely to Stanford University, according to three US officials. Kahl, who served as national security adviser to then-Vice President Joe Biden, has not ruled out returning to serve in a second Biden administration. Sasha Baker, the deputy under secretary of defense for policy, could move up to the head policy job, at least in an acting capacity, while Mara Karlin, the assistant secretary of defense for strategy, plans and capabilities, could be nominated to replace Kahl.