Senior aides to the defense secretary, Pete Hegseth, conducted polygraphs on their own colleagues this spring, in some cases as part of an effort to flush out anyone who leaked to the media and apparently to undercut rivals in others, according to four people familiar with the matter.
The polygraphs came at a time of profound upheaval in his office, as Hegseth opened a leak investigation and sought to identify the culprits by any means necessary after a series of sensitive disclosures and unflattering stories.
