I think Jews should not serve in the US military, Police forces, US Customs, stuff like that sure. But the military for the Jews is only the IDF.
I agree with Cosmo. I don't mean to say that these institutions are all bad, but there is obviously going to be anti-semitism every step of the way or at least just a subtle, unspoken bias against you because of being Jewish.
I think if you want to join a military you should join where your Judaism is considered an
asset and not a
liability.
Plus you don't want to waste your life being directed by supervisors who might be anti-semitic. They would use you as a pawn. In Israel, at least you would be able to fulfill your maximum potential.
BTW: I was at a shabbat dinner on Friday and there were some guys there who served in the IDF. They said the IDF soldiers can't accomplish anything now. They looked like good guys, so this confirms my theory that IDF will be awesome, they are just waiting for someone with guts (like Chaim) to take over leadership of Israel and unleash their potential.