If handled properly (and, today in the US Military, it often isn't), there's no reason that having women in support roles should cause any great number of significant problems. While behind the front lines, a combat soldier isn't going to be killed or get others killed because he's ogling or flirting with a female soldier, and he isn't going to be put in the position of trading the life of a bunch of men in order to "save" a mortally wounded woman. The dynamic is VERY different when combat is involved.
Many many wounded men have found great comfort in the female medical staff that took care of them. Women do a great job as doctors, nurses, and medical technicians, for example, and these are always needed in combat.
Other jobs, such as supply, electronic repair, computer tech/engineer, and thousands of others can be done by women without a significant reduction in morale or productivity IF MANAGED PROPERLY.
The problems come when the leadership starts favoring the women and places their burdens on the men. This happens in some places today, but *it doesn't have to,* and in many units it doesn't.
Clearly, though, if women are to serve, they should meet the same standards as the men, and expect to do the same work to the same level of performance. The Army kicks out MEN who don't meet those standards, so there shouldn't be an issue if they do the same with women. As long as that basic tenet is followed, issues will be minor.
-Troy