Ban-the-bombers holding missiles back ring military man? (8)
I believe the answer is:
commando
'military man?' is the definition.
(commando is a type of soldier)
'ban-the-bombers holding missiles back ring' is the wordplay.
'ban-the-bombers' becomes 'CND' (Campaign for Nuclear Disarmament).
'holding' is an insertion indicator.
'missiles' becomes 'ammo' (short for ammunition).
'back' says the letters should be written backwards.
'ring' becomes 'o' (letter resembling a ring).
'ammo' written backwards gives 'omma'.
'cnd' going around 'omma' is 'command'.
'command'+'o'='COMMANDO'
(Other definitions for commando that I've seen before include "Soldier trained for carrying out raids" , "Green Beret" , "specially-trained soldier" , "One soldier" , "going this way is unbriefed?" .)