President-elect Donald Trump stunned the Pentagon and the broader defense world by nominating Fox News host Pete Hegseth to serve as his defense secretary, tapping someone largely inexperienced and untested on the global stage to take over the world’s largest and most powerful military.

The news was met with bewilderment and worry among many in Washington as Trump passed on a number of established national security heavy-hitters and chose an Army National Guard captain well known in conservative circles as a co-host of Fox News Channel’s “Fox & Friends Weekend.”