Women are serving right now in the current wars. Of course they can. I find the wording of "allow women on the front line" troublesome. Women are citizens and don't need anyone's permission to do their duty.
Could I ? No doubt, when I was a 22 year old. Now, not so much. I couldn't begin to hump an 80 pound pack all day.
But if the question is "Can you kill someone who is threatening you or your companions?" You bet!
The real question is "Will the men around them see them as equal soldiers". And that's a different topic.
WHAT I HAVE LEARNED SO FAR, MOSTLY THE HARD WAY
• Do only safe sex. Never have sex with someone crazier than you are.
• Don't marry or move in together before you're both at least 25.
• Don't have children until you're married five years or at least age 30.
• Put 10% of your salary into savings every month no matter how broke you are.
• Don't ever screw around with the IRS.
• Keep a handgun on your bedside table.
• Don't smart-mouth judges, or cops who stop you on the road.