The Nazis were evil. It's tragic if the Poles rallied their subversive efforts around an even more-murderous ideology.
I'd like to think this particular slant was chosen so the film-makers could slide the flim by their commie overlords of the 50s, and not b/c anybody 10 years into the commie occupation could possibly believe Marxism had anything to offer them.
Still, if you can get by that point, it's an interesting story about the Polish underground as acted out by teenagers, for the most part.
TCM should change its synopsis of this movie: ''A young man loves a resistance fighter in WWII Poland." That barely qualifies as a red herring.