Prior service here / US Army, US Air Force... it’s known as a high and tight. One’s head cover, patrol cap, beret, or peaked cap otherwise known as a bus driver’s hat is better held tight on the wearer’s head by a fresh haircut, especially if it is high and tight.
Also during WW II, airborne paratroopers jumping into Normandy gave themselves Mohawk haircuts and put on “war paint’. The high and tight is an acceptable substitute for the Mohawk and carries with it a warrior ethos, similar to what the Mohawk haircut did for the jumpers going into battle during WW II.
Get some! Ooorah! Death From Above! Airborne! Chairborne! (legs) (naps) (inside joke)
Special Operations also sport a warrior ethos look. Think of bikers on steroids... except you’d be wrong. Think of raiding Vikings. Bingo! ;0)
SOURCE: By Photo Courtesy of PEO Soldier - https://www.flickr.com/photos/peosoldier/4639655696/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11309362
Thanks for the additional information.
I noticed Trump had a new hair look a few days ago too.