That would be an interesting twist on the KR story - the nationalists come to power in Germany and become expansionist, and just like OTL WWII the democratic USA finds itself allied with the Reds in order to defeat Germany.
Another thought that occurs to me in that sort of scenario is that relations between the Allied powers would be way more rocky than in OTL. At least in OTL WWII the American generals did not have to liase directly with Zhukov or Konev until very late in the late (can you imagine what would happen if Zhukov and Patton got into an argument,