New arsenal contains conflicts (4)
I believe the answer is:
wars
'conflicts' is the definition.
(I know this)
'new arsenal contains' is the wordplay.
'contains' says the answer is hidden in the clue.
'WARS' is hidden within 'new arsenal'.
(Other definitions for wars that I've seen before include "Armed conflicts against enemies" , "See 8" , "- - of the Roses" , "Battles" .)