all for one and one for all / one for all and all for one

one-way UAV / one-way attack UAV (OWA UAV)

train all ranks one rank up

Select one or all motors

all-wheel drive / all wheel drive

observation and fields of fire, avenues of approach, key and decisive terrain,obstacles, and cover and concealment (OAKOC)

fight one's way into the target and out

swift and flexible changes from one formation to the other

allow to look anywhere and still have information in one’s eyes

commission, to resign one’s commission

complete one's tour

force one's way

hoist / strike one's flag

inch one's way forward

one day’s supply

one-man turret

one-piece

one-piece base

one-shot weapon

one-time report (on status of equipment etc.)

one-time report

one-up

overstay one's leave

prescribed range (running-time on one fuelling)

push one's way

reverse one's field

strike one's flag

tighten one's hold

wet one's stripes

win one's epaulets

celebrate (one's) stripes

give away (one's) position

lie upon one's arms