The funny thing is that the United States served with several armies in Afghanistan with openly gay armies.... England, Canada, Israel. Is there something about our soliders that they're too fragile to handle openly gay men? LOL.
The real problem with don't ask/don't tell is that it's arbitrary. If your officer doesn't care, then nothing will happen to you. But if your officer doesn't like you, for whatever reason, they can use your sexuality as a weapon to throw you out of the service. It's not really Don't Ask/Don't Tell, basically if anyone mentions that you are gay, you can be targeted. Further, say you're the target of anti-gay harassment in the military service, even if you don't happen to be gay. Are you going to report the abuse to superiors and thus give them a reason to eject you from the army? No way. In fact, gay soldiers are less safe in a don't ask/don't tell environment. Either the military should just ban all gays or let them serve without fear they could lose everything with one wrong move.
Basically we have an army where you can enlist if you're a high school drop-out, have been treated for mental illness, committed minor crimes but not if you're gay. Does that really make any sense?