If you insist on having separate showers or bathrooms for men and women when you're in the middle of Afghanistan, get the heck out. I'm all in favour of letting anyone who's physically capable of a job, do the job (for equal wage and with equal rights etc). If you need special accomodations, you're not equal for the task.
Of course, while I've met women who demanded female soldiers are supplied with all kinds of nonsense (for the record, "putting a garbage can in the toilet" isn't ridiculous nonsense; "putting up a separate-and-equally-large shower facilities for 2 women as for 48 men" is), I've never actually met a female combat soldier who asked for that. There's a difference between "showering together" and "sharing shower facilities". If you can't do that because "eww man cooties", you don't belong in a war zone. If you can't because the rest of your unit will rape/abuse you, the rest of your unit doesn't belong there.