Participant in old war that’s throttled by fighter (5)

I believe the answer is:

boxer

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'fighter' is the definition.
(I know that boxer is a type of fighter)

I can't explain the rest of the clue.

(Other definitions for boxer that I've seen before include "one that's accustomed to fighting" , "Pug - dog" , "Tyson, perhaps - type of dog" , "Breed of stocky short-haired dog" , "Pugilist - dog" .)

I've seen this clue in The Independent.

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