This is essentially the same question as the "women in combat zones" issue that arose recently in Congress. Some congresspersons wanted (I believe in good faith) to keep women out of harm's way by prohibiting them from occupying positions that place them near the front lines, in the areas of greatest personal risk. Even though women are not expressly assigned to combat positions, their support roles are vital to operations, argued the Pentagon, and sometimes that necessitates their presence near the firing lines.
I can see arguments for both sides. I remember being on a date in a cocktail lounge when the guy I was with got into an altercation with the bartender. I was right next to the "combat zone". They both reached across the bar and grabbed each other and I got an accidental elbow in my ribs. As I picked myself up off the floor, I realized just how very strong most men are compared to, well, me, at least, and how much more force they can exert than I can. At that point, I came to understand something. Men can do things physically that even the strongest women can only dream about. That said, bullets are the great equalizer. All the muscle in the world can be stopped dead in its tracks by a well-placed, adequate-caliber bullet (preferably hollow-point). But in combat situations, you can't always rely on bullets. Sometimes, it will have to be hand-to-hand combat in a war zone. A larger woman in excellent physical condition with martial arts training might have a chance in such a situation against an average or smaller man -- provided he is unable to restrain her. Once her limbs are restrained, it will be much harder for her to break free than it would be for a male. Most combat hand-to-hand fighting relies on upper-body strength, while women's greatest physical strength is in their legs.
So, is it fair, right, or just to send a woman into harm's way? My answer would be that each woman should decide for herself how much risk she is willing to assume. Is it fair that men are not given that same option to decide? Well, they are not the ones being asked to confront physical strength much greater than theirs. Men in combat in general have a fighting chance against their male enemies. With women, it's not a sure thing, so it's fair to give them that choice. Let those who wish sign up for front-line or even combat duty if they think they're up to the task. Then the Pentagon and the chain of command can feel free, with no moral misgivings, to assign these women to duty in combat zones. The Pentagon could even take this a step further and ask women to assess the degree of risk they are willing to assume in combat areas on a scale of, say, 1 to 10 or 1 to 100, and assign women accordingly.
That way, no one can say that women are not being give equal opportunity to serve, and it should also be understood that women who recognize their physical inadequacy to confront enemy male combatants are being realistic, not cowardly, and their male colleagues should respect them no less for making the contributions they are able to make. The military, after all, is about physical strength, and that women want to be there at all demonstrates their desire to contribute as equally *as they are able* to the defense of their country.