In what ways is this movie like Casablanca?
There were two movies this reminded me of. One was a movie of the same era that is an older movie from the 50's or so [ just found it, "Berlin Express" ( 1948) ], and the other is Casablanca. This movie is practically a clone of Berlin Express, but if you find out about Berlin Express, it is so very much better than "The Good German" because it was filmed at the time these events were happening, by someone who was there and wrote a story to capture the feeling.
Obviously they were playing off Casablanca, almost comedically at the end with the propellor plane on the runway, but also in the plot of having a cryptic woman as the main character of the movie, despite it focusing on all the men and politicians and history. Yet, despite these vague similarities it is not set in a foreign land or during war and it doesn't have the same vibe or anywhere close to it ... and it also ends with no real point or conclusion, whereas Casablanca ends of resolved happy note.
Certainly Casablanca is the better movie by far, and more sensible movie. The Good German really made no point about any good German.