Can a platoon sgt tell a female soldier that she is required to wear a bra when in civilians?

When you entered basic, you were issued underwear. T shirts, boxers/panties and bras. You wear in uniform, what you wear what you were issued. When wearing civies, you follow local regs say you WILL WEAR. You represent the military 24/7/365. When you were growing up and going out to play, on a date or to summer camp, didn't your mother ask you if you were wearing clean underwear? Let me put it to you in a simpler way. You're wearing a T shirt, no bra. It's a really hot summer day/night, you sweat (glissen as a woman) and your T short gets soaked. What's going to attract more attention? The same will go for cold weather.

Wow

If it offends you DON'T LOOK

Likely can tell her that when she is on post.

When I was a PSG, we were on duty 24/7/365... even when on pass, and subject to be called to duty on a moments notice.
We were also told that, if it was issued to you... it's part of the uniform, and we will ALWAYS present a professional appearance, on or off duty, because we Represent the U.S. Military.
ESPECIALLY when deployed in a foreign Nation, where we WILL comply with THEIR Customs... to prevent INTERNATIONAL INCIDENTS.
idk where you are, but if it's anywhere in the mid-east, you are ASKING to get your head cut off.
Either way... YOU make your OWN Choices... if you choose to disobey, and find an Article 15, or Courts Martial, in your face... don't cry... willful disobedience is what GETS SOLDIERS KILLED ;)

As you haven't given us some much-needed info, such as where you are currently stationed, it's difficult to answer this. The only possible reason I can perceive for this type of directive is if your lack of wearing a bra may be culturally insensitive to the local population due to cultural traditions, religious reasons or customs.

I suspect it depends on if you,re in a SMU which I doubt. If you're in a sorry assed leg CSS unit then NO. I know they couldn't make me wear my bra.

I'm not sure depends on the organization. If its some sorry assed leg support unit I think not. I know they couldn't make wear me bra.

There is not one person in any branch of the United States Corporation’s Military who stands behind their oath because if they did, 99% of the discussions on this forum would have never been brought up. Not one servicemember honors even one word within the constitution for the United States. There is not one article or amendment of the constitution that speaks about what anyone must wear. Freedom of speech is there as well but if anyone puts you in your place and you outrank them, you want to push paper on them. All of you are only in the military for the power and control it gives you. Not one of you even care for the blood on that document. This shouldn’t even be a discussion but again this is entertainment for those of you who thrive from the exercise of a power you truly do not have.

After I made a comment, I read a bunch of comments. You are putting way too much into your right not to wear a bra. You are in the Army. If someone in your chain of command told you you need to wear a bra, then wear a bra. Seriously, you are going to jeopardize a promotion or your career because you don't want to wear a bra. This is such a sticky situation, you're not going to know the real reason you got passed over. They're going to find something else that you're not perfect at and blame it on that.