Revise commercial involving soldiers (5)
I believe the answer is:
amend
'revise' is the definition.
(I know that amend is a type of revise)
'commercial involving soldiers' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'involving' indicates putting letters inside.
'soldiers' becomes 'men' (men can mean a group of soldiers).
'ad' enclosing 'men' is 'AMEND'.
(Other definitions for amend that I've seen before include "Make small improvements to" , "Rectify" , "Revise" , "Modify - edit" , "make an improvement" .)