Everyone seems to be using 'combat' as a blanket term. There's really a big difference between Spc. Joe Schmuck support person who gets in a firefight, and Spc. Tommy Toughnuts infantryman who walks around all day looking for a fight.
I have a female friend from the Army who had been attacked on convoys in Iraq and had people shooting at her, and she shot back. That's combat, no doubt.
I also have friends who were infantry, and a couple who were Rangers. One of them spent 18 months straight in Afghanistan dragging a sniper rifle up and down mountains, setting up ambushes and attacking Taliban. One of my Ranger buddies was in Iraq breaking into buildings and chasing down people in the streets and arresting them.
All these people 'served in combat', but it's a big frickin difference. My female buddy was totally competent in her MOS, passed her PT tests no problem, and was generally one of the more squared away people in our unit. I was glad she was in my squad (we were marksmanship instructors in this unit mind you, not infantry). BUT I can tell you there's no way in hell she could have physically done what my infantry friends did day in and day out.
That's just one example I guess, but something to think about.
edit: spellinz