The word "Volk" means something similar to what the words "folk" or "people" might mean to us. So I don't see how that in and of itself is unchristian. If those concepts are unchristian then we would have to say that all national states are unchristian and that only a theocracy, perhaps something like the old Papal states, is genuinely "Christian".
"I took part in the evacuation of Dunkirk. Our soldiers felt very badly. I helped to fish out Germans from the sunken Bismarck, which received the greatest number of torpedoes in history. I saw the population of Malta sitting in the cellars for many weeks. I saw Malta being bombed incessantly and deafened by explosions of bombs and shells. They were exhausted from constant explosions and alarms. I lived through the sinking of my own ship. I know about jumping into the water at night, dark and without bottom, and the terrifying shouts for help of the drow- ning, and then the boat, and looking for the rescue ship. It was a nightmare. I drove German prisoners captured during the invasion of Normandy. They were almost dying from fear. But all that is nothing. The real, terrible, unspeakable fear I saw during the convoying and repatriation of people to Soviet Russia. They were becoming white, green and gray with the fear that took hold of them. When we arrived at the port and were handing them over to the Russians, the repatriates were fainting and losing their senses. And only now I know what a man's fear is who lived through hell, and that it is nothing compared to the fear of a man who is returning to the Soviet hell."