A certain amount of social indoctrination occurs as well, where males are taught to believe that they have the "right" to expect certain favours from women, in return for their status as "warriors." At the same time, they are also indoctrinated with the idea that women are somehow inferior, and that their presence is a possible threat to the young men's masculinity.
This socialization process also is worked on women, many of whom internalize the message that they "owe" such things to their male colleagues, and that the proper way to progress is not by competence, but by forming liaisons with male superiors. In this very gender sensitive environment, competency by female personnel is marginalized and downplayed; top female performers often are labeled as "lesbians" or similar epithets.
In addition, lower enlisted culture places great value on drinking and "partying" ability, not unlike that of the average college student. Unlike the college atmosphere, however, the military atmosphere couples this hedonistic ideology with unit insularity and a sort of hyper-macho code where women are expected to acquiesce to their roles as prizes and objects.
The long and short of this is: Mamas, don't let your daughters grow up to be soldiers!