Argument with servicemen raised (3)
I believe the answer is:
row
'argument' is the definition.
(I've seen this before)
'with servicemen raised' is the wordplay.
'with' becomes 'w' (abbreviation).
'servicemen' becomes 'or' (abbreviation for Other Ranks).
'raised' says the letters should be written in reverse.
'w'+'or'='wor'
'wor' backwards is 'ROW'.
(Other definitions for row that I've seen before include "One of the ranks" , "'Quarrel, dust-up (3)'" , "Propel boat manually" , "Falling-out" , "Argument; line" .)