Come on... Don't even go there. They were committing atrocities and the trials demonstrated that any reasonable person would know that the orders themselves were illegal because of their nature.
Here, the orders themselves are perfectly legal, nobody is questioning that. It is the issuing authority that is being questioned. And there is a world of difference there.
Nobody is accusing Obama of ordering our troops to commit atrocities. Clearly, any soldier would be expected to refuse such an order. We were all given classes on the Geneva Convention (as were you). There are many situations the average soldier is expected to recognise the illegality of orders. They never once mentioned in those classes 'or if you heard that the CinC's birth certificate wasn't in order'.
I'm being sarcastic but I think your comparison is bogus. In the case of the Nazis the orders themselves were wrong- but not the authority issuing those orders. There is a difference.
“Here, the orders themselves are perfectly legal, nobody is questioning that. It is the issuing authority that is being questioned. And there is a world of difference there.”
If the issuing authority is proven to be illegal, then the orders that are issued by said authority are thus illegal.
Actually (not to go off topic) but that's not entirely accurate.
As a Jew, the last thing I'd ever want to do is to defend the Nazi's, but they were prosecuted for crimes committed before the laws were written to make them crimes.
When they did their horrible deeds, the UN didn't exist and the Geneva Convention didn't happen until several years after the war. At the time of their crimes against humanity, there were no laws saying that what they were doing was illegal. They were citizens of a sovereign nation following their own laws.
I don't know how they justified the prosecutions, but they did and I am glad for it. One lesson I've learned from this is that the law is written by Man and it is imperfect. Just because it's legal, doesn't mean it's *good*.