Carried on, as war (5)
I believe the answer is:
waged
'carried on as war' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for waged that I've seen before include "in paid employment" , "Bet or conducted" , "Receiving regular payment for work" , "Carried on (war)" , "In receipt of pay for work, employed" .)