I really don't see how that effects their ability to do their job and how their gender identity affects national security. If a transgender person was working in an office and then they were told because of your gender you can't carry on filling out spreadsheets because you have gender dysphoria and somehow that makes you confused while doing your job is completely absurd. 15,000 jobs will now become vacant leaving holes in front line service and intelligence, for example. That loss of skill and talent is much more detrimental to the military service.