Western countries should have national service of 18 months, drawn as a lottery, absolutely NO exceptions, unless medically deemed unfit, crim record, ect. No exceptions for College, or any of that crap, if your name is drawn your going, unless there is a very, very good reason. The whole notion of an all volunteer force makes these kind of issues inevitable. You would not need females in so many roles of there were enough male recruits coming into the services at reliable #s. The USN for instance would not need to rely on females crewing combat vessels, especially subs.
Volunteers? thats fine, and a desirable and honorable tradition, but there is nothing wrong with saying to a small percentage of citizens on an annual basis (the # would vary from year to year), that your country needs you, and you are in for 18 months, due to certain recruiting goals. This idea that we have a choice in not serving, while hiring more and more "contractors" and "outsourced services" and now females, only reyling on a very small slice of the overall citizenry is at its core, wrong headed, imho. The population over time is also conditioned to think that its ok not to participate, that "somebody else" will always do it. Is that what we want to foster as an idea?
If you dont think we wont go the same way Rome did, your wrong. At the end, few of its citizens felt it was "their" duy to fight the Barbarians, no, rather they just said "lets buy more foreign auxiliaries" while we live the good life. It worked...for awhile.