Obviously based on this whole thing in America. A quick look at Wikipedia says the following countries allow it.
https://en.m.wikipedia.org/wiki/Sexual_orientation_and_military_service
"Australia, Austria, Belgium, Bolivia, Canada, Czech Republic, Denmark, Estonia, Finland, France, Germany, Israel, Netherlands, New Zealand, Norway, Spain, Sweden, and the United Kingdom."
So now loads of people are up in arms saying that it's discrimination for America to not allow trans people to serve. Trump being attached obviously makes it more visceral.
Personally, I think if the entire process is done and over and the person is comfortable with their new sex, it'd be fine. But a 40% suicide rate, in America anyway, is pretty insane, along with the extreme stress a person must be under before and during the process. So in my opinion, a blanket "no" makes more sense than a blanket "yes".
Gender dysphoria is a mental illness, intuitively and according to the WHO. It's not a sexual preference, though we all forget that because of lgbt. While harsh, you're giving a gun and the responsibility of saving lives to a person who wants to cut off parts of their body. You can't just ignore suicide stats.
The more rapid fire among you probably think I'm anti-lgbt but that's to be expected online. I don't care what other people do with their bodies. This isn't about that.