Even in boot camp it looks like they don’t get them.
So how come only the guys get them?
Last I saw, they do, they just don’t (usually?) get a buzz cut, just a short cut.
Women in the military are permitted to have long hair as long as they wear it up and it doesn’t interfere with wearing the uniform hat correctly. At least that was the rule when I was in ('73-'84)
I got my hair cut before I went in just to make it easier on myself. A year later, I decided to let it grow, but it was more of a pain than it was worth keeping it off my collar.
As to why - I’m guessing that because traditionally women have longer hair, the military adapted to it.
Yep. Still is. . .
You can technically wear your hair any way you want, so long as it presents a neat, professional appearance (ruling out fads such as orange mohawks) and doesn’t interfere with either mission requirements and/or military headgear (that radio headset has to fit, as well as the flight helmet - no hairbuns, ladies!)
Not that an orange mohawk wouldn’t instill fear in my enemies. . . 
Tripler
aka “Mr. #1 on the sides, and short enough to be neat on top.”
I was under the impression that women did get a haircut upon going into basic training, just as the men do, but they only get a short, but still feminine (Not a buzzcut, obviously) cut. After that, they can let it grow out, as long as they keep it neat and off their collar, like the other people mentioned.
One of the militaries inconsistent equal treatment of women.
You may not wear your hair any way you like it. The hair must not exceed 3 inches from your head in any direction when worn in uniform. It must not touch your collar. Also, braids, ponytails, and some other styles are verboten.
http://www.af.mil/news/Aug2002/81902136.shtml talks of a Senior Airman getting her hair cut. It is over 14 inches long, it would not be that long if she had it cut in boot camp.
The requirements may be different for those entering the service academies.
As for why women are not required to cut it, perhaps the military trusts women to be grown up and not let their hair interfere with their duties.
The truth is that the military does not expect that women be men or men be women. The do not require women to nearly shave their heads and they do not require men to sleep in bras during basic training. The short hair for men reflects a cultural norm or ideal for men. That is not the norm or ideal for women. Until that changes, the regs are unlikely to change.
This thread is better suited for GQ. I’ll move it for you.
Cajun Man - SDMB Moderator
But I knew a Marine Corps. officer who had very long hair. Whenever she was on duty it was kept in a tight bun, but other wise she often had a ponytail that almost went down to her waist.
All braids are out?
If so - there goes the military as a plan, ever.
Hmm. Just read that back to yourself.
I was referring to styles that were acceptable in uniform, not out of it.
A buzzcut is a traditional military haircut for males, but a buzzcut on a female would be considered faddish. And faddish haircuts are against regulations.
So you might say that the same rule is applied to men and women - no fad hairstyles.
There are other differences in grooming and uniform standards for military men and women, e.g. women may wear (certain types of) earrings in uniform. The differences reflect social norms. To force military men and women to adopt the same uniform and grooming standards would separate them to much from normal society. IMO.
Because they’re hippies. 
My best friend from high school had to cut her hair to just below her ears. She told me that the main thing was it had to be a certain length above the collar, about two or three inches I think.
I remember a girl in basic (USAF) who had hair down to her ass. She kept it up tight thought and kept it thru basic.
I had hair almost to my butt all through basic and the three years following. I kept it tightly up, no wispies or anythng falling down, with a french braid folded under at first, as it got longer a braid wrapped round itself. Here were the rules -
No hair accessory could show (bobby pins, hair tie, anything)
No wispies (small short baby hairs floating about the face or neck)
We had just as much time as the men to get ready, no more, no less
I looked at it as the equivalent of the men having to shave before PT, I’m sure that was inconvenient for them. I did consider for a time (satrt of basic) getting my hair cut, but left it long. It gave me a way to feel “out of uniform” whn I put my civvies on.
On the plus side, I got very, very good at putting my hair up fast and neatly 
Be careful when you say this: other services may or may not have the same policy.
Hey Poysyn, you weren’t PPCLI by chance, were you?
Tripler
I’m not, but I have a few friends that were/are.
Well, as long as boys look like boys (shorter hair) and girls look like girls (longer hair), I guess I feel well-defended. Don’t ask; don’t tell.
Does anyone think that short hair or a butch cut on them might look a little too ‘gay’ for the army, etc?
handy: That might explain why men can’t have long ponytails as well…