Ilsa is fiercely loyal to her husband, Laszlo, and the political cause—resistance to the Nazis—he represents, but the truth of her sentiments is constantly suspect. She claims to love Laszlo, but she also claims to be in love with Rick, both in Paris and in Casablanca. We might suspect that Rick is her great passion and that only circumstance and political necessity prevent their union, but Ilsa never makes the distinction clear. She has good reason to tell Rick she loves him in Casablanca, since she needs the letters of transit he holds. Her motives are always shadowy because she always has possible, logical ulterior motives, and she maintains a cold detachment that prevents her from being understood. The letter she sent to Rick in Paris so many years ago, saying she could never see him again, is evidence of her ability to shield her true feelings from those who love her the most.
Ilsa clearly has suffered from the whims of fortune more than any other character in Casablanca. First, her husband is arrested and rumored to be dead. When he reappears, she must run with him throughout Europe with the Nazis always on their heels. She meets Rick and falls in love, only to have to leave him, then meets him and perhaps falls in love with him again, only to leave him once more. No matter whom she truly loves, she has not had an easy life, and her fate is the most tragic in the film. At the airport we can see that for Ilsa, the possibility of a happy ending does not exist. Ilsa herself may not even know what her own happiness would entail.