The main question for me is whether enough women ARE physically capable of being "front line soldiers." Possibly for some infantry groups, but for rangers, infantry marines, special forces, navy seals, ISA, SFOD-D, etc, I find it hard to believe. It takes well above average physical abilities even to be in a basic marine infantry unit, and the vast majority of men can't do it. If women are on average significantly less physically capable (strength and endurance) is it likely that more than a handful will be capable of doing what such a minority of men can do?Man or woman, if one can be trusted to perform the physical and mental duties required of a frontline soldier, then I see no reason to not allow that person to be there.
And if there are a small minority of women who are physically capable of doing it, how many even want to join the military?