Women serving on the front lines is quite a bad idea. For one, they do not naturally have the physical and emotional strength that men do. Even if a woman passes the "male test," I still do not think she should be allowed on the front lines of combat. Why? Well... I'd rather not go into too much detail. Another thing to consider: what would happen if she was captured? I don't even want to think about it.
All in all, women don't belong on the front lines, and we should not put them in the situation. Not that I don't respect all men AND women in the military, but until I see a crop of female linebackers that can crash through an NFL offensive line and break Tom Brady's ribs, I don't even entertain the notion that women are fit for combat.
Whether certain people want to believe or just simply ignore the fact that women and men are not the same. Let's for instance look at history and how combats were initiated or involved by mostly if not all men. In today's society, technology has made it easier for men and women to participate in almost anything that were once thought women could not handle. Even though it true, we have to follow our instinct and realize that women are at a unique risk in combat
A person engaging in combat is at risk of being killed or injured. I don't know how that would be a unique risk for a woman over a man. Perhaps a woman taken as a prisoner might have the additional risk of being raped, but men and women both hold the risk of being tortured or treated brutally, so I don't think rape should be considered as a separate case from that. I used to consider that women might have children at home that depended on them and so should not be held to serve roles in combat. But then I realized that men do also, they have as much to lose as women do when they go into combat, so I don't think women should have a special dispensation for any reason.
Women that want to do this job and are deemed capable of doing so are not a liability. They are no more in risk of getting injured or killed than the men that they serve with, while it cannot be argued the gender is generally weaker than males as a whole it doesn't mean they're all pathetic little flowers that cannot fight on the front lines. If they got that far they did because they deserved to.