SeRosewater

That's exactly it! Thank you very much for your help! I'll be watching this movie again, this time fully attentive and healthy.

I was half-conscious in the hospital one night when I was watching this movie, so I don't remember the character's names. I'm also unfamiliar with a lot of actors and actresses, so I couldn't tell you who was playing these roles. The story (from what I gathered, I could be wrong on a lot of this) followed an American who was partnered up with another American woman on assignment. Unfortunately I don't remember what the assignment was. He eventually fell in love with her, and they began to date. At the same time behind her back, he was already seeing a German woman who was or formerly was affiliated with Nazi. She lived in a bit of a run-down flat, and sang at a local club. One night when the Americans went out on a date, they went to the club the German girl sang, and she took advantage of the situation, exposing the American boy for his two-timing to the American girl. I forgot what happened during this chunk of the movie, but the next scene I remember, had the American girl singing to entertain a bunch of men. I don't remember what song she sang. The club was raided, and the American girl was in a bind. (I think she was missing her Passport.) The German girl helped her out (honestly, or with an ulterior motive, I don't remember.) using her popularity and/or ties. Sorry for the lack of information. I tried searching with keywords, but only come up with the Sound of Music for some reason, and I know that's not the movie I'm looking for. Thank you in advance!