It is a deep pleasure to watch actors exude cool from every pore. Bogart, Bacall, and Sheldon Leonard are so cool they force habaneros to jump into an icebox, just to warm up. The direct opposite of this deep chill is Walter Brennan who allows himself to be mocked in every scene he is in, and that only increases the cool in the other three characters, by contrast.
I hate to say it again, but Howard Hawks is a genius of entertainment. He can take a Hemingway novel and make it comedic, while not reducing any of the drama. This film has so much in common with Casablanca, but it is so much better because the tone is less heavy-handed, and the writing is just a little better. Perhaps Casablanca makes better noir, but To Have makes me want to re-watch it, just out of sheer enjoyment.
The film isn't perfect. In general, it seems to be a symbol of how France needed America to pull itself out of it's scrapes in WWII, because France is fundamentally cowardly. Bogart is the epitome of America, rough, hard minded, business-like, and fiercely loyal. In real life, he wouldn't make a great hero, but in this particular plot, he fits perfectly. I think he is too mean in Maltese, too comedic in Big Sleep, too underdeveloped in African Queen, but here he is perfect-- tough, but fair minded; smart, and ready to laugh; knows when to be distant and when to be romantic. This will be one of a couple of my favorite performances by him.