not true.
im in the aviation field. im an avionics technician with 13 years in the USMC and have not once seen combat. yes i have deployed in SUPPORT of the wars, but us mechanics are nowhere near the fight.
but, i can also put in a few comments about the AF as well. my little brother has been in the AF for about 6 years now. he deploys more often that i do, but for less time away per deployment. where i may deploy for 6 months every 2 years, he goes for 3 months sometimes 2-3 times a year. his job is the same as mine is, just a different branch of the service.