>Nowadays, you typically have the right to refuse an order if you know it's illegal, but I doubt that was the case in the SS in 1944
That was the breakthrough of the Nuremburg trials. Judges cut through that and established the principle that everyone in the SS could have known they are committing genocide and could have known that a genocide is not covered by the rules of war. That's why you can refuse an illegal order in Western armies now.
The alternative would have been that everyone in the chain of command had claimed duress up to the NSDAP leadership - and those were mostly dead by then.
Post-Nuremburg, everyone knows that you will get punished and the higher your rank, the worse for you if you are part of genocide. Ideally. In reality, a lot of war crimes and genocide still goes without punishment.
That was the breakthrough of the Nuremburg trials. Judges cut through that and established the principle that everyone in the SS could have known they are committing genocide and could have known that a genocide is not covered by the rules of war. That's why you can refuse an illegal order in Western armies now.
The alternative would have been that everyone in the chain of command had claimed duress up to the NSDAP leadership - and those were mostly dead by then.
Post-Nuremburg, everyone knows that you will get punished and the higher your rank, the worse for you if you are part of genocide. Ideally. In reality, a lot of war crimes and genocide still goes without punishment.