I think there is more to this than DC's (or Kanigher's) desire to keep the majority of its war stories set in WW2.
If you look through the entire body of what DC was publishing in the 50s & early 60s, there is virtually no mention of the Reds and a protagonist in any stories: superhero, mystery, sci-fi fantasy or war. Even the espionage books (like DANGER TRAIL - King Faraday, Johnny Peril, etc.) never mentions the Reds by name...the adversary is always "a foreign power".
This really shows clearly when DC takes over BLACKHAWKS from Quality and all the Red villains/themes vanish.
Marvel, on the other hand regularly injected the Red Menace into all its titles...right up to its super-hero rebirth (the FF, Hulk and Iron Man all had Red Menace themes involved in their origins).
It would be most interesting to investigate the politics of the owners and editors of DC during this period .. to see if a pattern develops.
Bill