here is his wiki bio.
Cohen-Watnick gained a Bachelor of Arts degree in History and Political Science from the University of Pennsylvania in 2008 before taking a position at the Office of Naval Intelligence after graduation.[3][4] Before joining the White House, Cohen-Watnick worked for the Defense Intelligence Agency (DIA), beginning in 2010, where he served in Miami, Haiti, Virginia and Afghanistan.[5] Cohen-Watnick was accepted into the training program for the Defense Clandestine Service.
Cohen-Watnick underwent training at Camp Peary (commonly known as “The Farm”), where he was trained by the Central Intelligence Agency.[5] He was assigned to Afghanistan, with a GS-13 rank.[5][6] He was temporarily assigned to the Defense Intelligence Agency Headquarters in 2014.[5] Cohen-Watnick left the DIA for the National Security Council on January 20, 2017.[5]
305 appears to be Army. there are plenty of military people here.maybe someone will eventually have something to say about it