English is not my native language either, so... Please let me explain: civil obedience, as opposed to civil disobedience, is what allows evil to exist, especially if it is evil of the state, dressed as good. Hitler was elected and civil obedience allowed him to still have power after he started doing really bad things. Civil disobedience is when humans think for themselves and don't let government order them to go to war, kill other people, etc. Civil obedience is saying "our leaders decided to kill those other guys, so I shall obey".
Now, what is Hitler guilty of? He did not press the trigger after all. And I'm not shifting responsibility, I'm saying that responsibility is... shared, for the lack of better word. There are different things here to consider:

1. Soldier is 100% guilty of pressing the trigger and killing another person.
2. His leader is guilty of giving the kill order. This goes up to the very top, in this case Hitler himself. His (or rather theirs, plural) crime is creating circumstances under which killing a person is a good thing. Is it not a crime? On one hand I understand your argument that ultimately the person executing the evil order (pressing the trigger) is guilty - this is of course true. But someone who used words to convince the soldier I also consider guilty. Process of training soldiers, as we can see in so many movies, is like brainwashing. Not even "like", it is brainwashing, it is mind control. Are the people brainwashing other people not to be blamed for what they are doing? Leader, officer, superior by giving an order is pressing metaphorical trigger. In this chain of command the only innocent being is the gun, because the gun is not capable of thinking for itself. And about people outside the chain of command... People producing bombs, people in governments buying bombs, simple hard working men paying taxes, thus providing money for the bombs... To a (very) varying degree we're (almost) all guilty.