kingrat, You may be right, that it has no appearance of being about the blacklist. But the setting and general tone of the film, that 'standard paranoia' is exactly what I was talking about. I felt especially from this movie that the incredibly high level of paranoia was symptomatic of the era right before and during the blacklist, and that the hierarchy of the "hive" and the gradations of evil shown seemed very like Hollywood, or the USA if you prefer. It could be the world of big business, if you choose to think of it that way, or of course the criminal underworld it says it represents. It's a lot like High Noon, except no one is left unscathed, even the hero. There are seemingly endless ways of assuaging one's conscience, with characters rising up from the dust to justify their actions and do it again. The setting doesn't really matter, it could be anywhere, but certainly the feeling of the movie is dog eat dog, and no doubt reflected maybe just a little of Dassin's anger and unease at his situation.JF, Eddie Muller mentioned that Night and the City was made in London, and the schedule was moved up, so that Jules Dassin could get out of the country. I don't see a connection to the blacklist in the script, except perhaps for the standard noir paranoia: you think they're out to get you, and yes, they really are.
For me, the 'little world inside the big world' theme gives this movie a strong connection to the blacklist - the way the blacklist moved from a politically motivated situation in Washington to encompassing the entertainment industry in Hollywood and other seemingly innocent areas of everyday life, like a spider web run by a rather hidden central leader with his fingers in every facet of his "empire"....and hirelings doing the 'dirty' work. The inability of the little man to control his own destiny or even his workplace without it destroying him or someone else. The way that corruption bleeds onto the innocent, and that a man doesn't even know he's doing wrong anymore, because he is substantially tainted by mere contact with the corrupt. It's about Power.
Specifically, maybe it hasn't got so much to do with the blacklist, but in tone, it has everything to do with it.