In love and in war, neutrality is difficult for Rick, Ilsa, and Louis to maintain.Rick makes a point of not being involved in politics. He refuses to discuss the war, shuts up Carl's attempts to tell him about meetings of the underground, and does everything in his power to present himself as nonpartisan. Later on, though, just as the United States abandoned neutrality in December 1941, Rick shifts from neutrality to commitment. His sympathy for the Allies has always been evident in small acts, such as his refusal to allow the Deutsche Bank employee entry into the back room of his casino, but his partisanship grows more overt as the film proceeds. Louis undergoes a similar transformation, and by the end of the film, neutrality seems an untenable position. Rick's Café, as well as Casablanca itself, is an oasis in the desert, a paradise far removed from the troubles of the world. Yet the underground and black market activities that take place at Rick's belie these qualities. The battle of German and French anthems that erupts in the bar shows that Rick's actually teems with political passion.
When Ilsa visits Rick in his apartment and confesses that she still loves him, she does her best to be neutral in the undeclared war between the two men who love her. For as long as she can, she tries to deny the dilemma she faces. When she finally acknowledges the dilemma and realizes she has to decide between Rick and Laszlo, she leaves the choice in Rick's hands. No clean, painless resolution is possible, and a choice must be made. In war as in love, Casablanca suggests, neutrality is unsustainable.
The first words of "As Time Go By" announce, "You must remember this," and in Casablanca, Rick, Ilsa, and Louis cannot escape the past and their memories. Even when characters try to flee from the past, and many do, the past catches up with them. On two occasions, Ilsa believes she has lost men in her life, only to have them reappear at the most inconvenient times. In Casablanca, Rick has created a lifestyle for himself that he believes will allow him to forget his painful memories, but the war and the flock of refugees hoping to escape to America remind him of an event or events from his mysterious life that prevent his return home. Likewise, Ilsa's arrival in Casablanca reminds Rick of their painful love story, the memory of which he has been trying to erase. The only character who suggests that the past can be escaped is Louis, who seems able to switch alliances breezily. Yet even Louis eventually acknowledges that his decisions have consequences. He recognizes that he must flee Casablanca because there is no escaping the way he helped Rick. He might want to ignore the past, but in this case he cannot.
Luck figures prominently in Casablanca, especially in Rick's Café. One of the bar's most popular activities is gambling, and one of Sam's most popular songs is "Knock on Wood." Mr. and Mrs. Brandel, the young Bulgarian couple, demonstrate how luck functions in the movie. "How is lady luck treating you?" Louis asks Mrs. Brandel as Mr. Brandel gambles at the roulette table. Mr. Brandel is trying to win enough money to buy two exit visas. For Louis, luck is the force that brings a beautiful woman like Mrs. Brandel to him and allows him to try to take advantage of her desperate situation. For him, luck is a lady, a sexualized concept that implies both seduction and powerlessness. Rick has a different view of luck, and he intervenes to help the unlucky Brandels, rigging the roulette game so the couple hits the jackpot twice, "miraculously" gaining the amount they need. When Mrs. Brandel approaches Rick to thank him for his generous deed, he dismisses her thanks by saying her husband is "just a lucky guy." This line has a double meaning. The literal meaning is that Brandel is just a lucky guy at the roulette table, which obviously isn't true. The metaphorical, and true, meaning is that he is lucky to have such a courageous, loving wife.
Particular people in Casablanca can bring both good and bad luck to each other. When Ilsa and Sam first speak, Sam tells Ilsa she should stay away from Rick because she's "bad luck" to him. But this statement isn't entirely true. Ilsa broke Rick's heart so tremendously that over a year later he still hasn't recovered, but, in this case, heartbreak has nothing to do with luck. "Luck" is simply a word used to cover up a more painful truth. Luck in Casablanca is also not entirely free of human influence. Ugarte is arrested while gambling, which suggests that he is unlucky to have been caught. The truth is that his own actions of murdering and stealing, rather than bad fortune, are the cause of his arrest.