As you point out, they fought for the survival of Germany - and the bombs on civilians had an astonishing impact on the soldiers. You said it, they felt Germanys survival was at stake. But if they had known that it actually was not (because the western allies soon would become a more dangerous enemy in the East), they would have loved to lay down arms.
We can be glad that we´re friends now, and we will never have to fight each other.
There's something about the line of thinking which absolves the German footsoldier that bothers me. I'll try to come back to it when I've got more time to think about it. I think it comes out of my deep conviction that political power is derived directly from willing cooperation. I wonder if fear and ignorance are any better than outright complicity? This may be a very American view. At some point the citizens are required to stand up to their governments or face more dangerous consequences. If WWII isn't a lesson in that, then I don't know what is. If WWII contains that lesson, then we all had best pay very close attention to it. Of course this is the excuse our war protesters (both European and American) are using now. But the Coalition doesn't have its Waffen SS standing behind its footsoldiers threatening to shoot them if they don't buck up and unleash our modern day equivalent of a blitzkrieg.
I'm still convinced that there was only one patriotic thing for German troops to do in 1938. There are bitter diary entrys written by veteran Japanese troops in the field and upon their return to civilian life that bemoan the fact that they were duped by their worship of Hirohito. Without these duped troops, there wouldn't have been a WWII.
I'm not convinced that we aren't responsible for what our leaders require of us. "I was just following orders" did not hold up at the Nueremburg trials. "I didn't know!" was the frequent comment made by citizens forced to walk through deathcamps just after they had been liberated. In a significant way, both were the same diabolical lie. Hitler spelled out his plans and he was elected to execute them. Most troops were loyal not just to the defense of Germany, but the idea that Germany could be a third empire. The rest is history.