Joe Kasper, Defense Secretary Pete Hegseth's chief of staff will leave his role in the coming days for a new position at the agency, according to a senior administration official, amid a week of turmoil for the Pentagon. Senior adviser Dan Caldwell, Hegseth deputy chief of staff Darin Selnick and Colin Carroll, the chief of staff to Deputy Defense Secretary Stephen Feinberg, were placed on leave this week in an ongoing leak probe. All three were terminated on Friday, according to three people familiar with the matter, who, like others, were granted anonymity to discuss a sensitive issue.