(6.1.2017) One position that is a source of tension is undersecretary of defense for intelligence, a powerful post that oversees all Defense Department intelligence agencies, which include the National Security Agency and the Defense Intelligence Agency.

Retired Lt. Gen. Michael T. Flynn, President-elect Trump’s national security adviser-designate, was DIA director until he was sacked by Director of National Intelligence James R. Clapper Jr. following a dispute with then-Undersecretary of Defense for Intelligence Michael G. Vickers.