The main issue with female troops isn't their own ability to serve, it's just that when they are placed with the guys then trouble ensues. Below are a couple of BBC links:

Women at war face sexual violence

"According to several studies of the US military funded by the Department of Veteran Affairs, 30% of military women are raped while serving, 71% are sexually assaulted, and 90% are sexually harassed.

The Department of Defense acknowledges the problem, estimating in its 2009 annual report on sexual assault (issued last month) that some 90% of military sexual assaults are never reported."

Women at war: sexual violence in the US military

That has got to be devastating to the ability of these troops to fight together.