Warfighter is used too widely IMHO, and often includes:
Medics
Drivers
Peace keeping troops
Plenty of medics, drivers and peace keeping troops have been in the thick of exchanging rounds with bad guys in the last decade in Afghanistan (some quite famously winning gallantry medals), so I have no problem with them being labelled warfighters. I prefer the term serviceman / servicewoman seeing as most service people are part of fighting wars in some way.
Clearly, the degree will differ, but there is an expectation there that all service people will do their bit in fighting wars*.
*Except adminers, obviously.
