If there is a single overriding theme in Notorious, it is that of trust—trust withheld, or given too freely—and "aptly, Hitchcock and Hecht chose to locate this romance about trust within the package of an espionage thriller, for spies are, of course, characterized by their exploitation of trust." T. R. Devlin is a long time finding his trust, while Alexander Sebastian offers his up easily—and ultimately pays a big price for it. Likewise, the film addresses "a twofold redemption: a woman's need to be trusted and loved, which will enable her to transcend a life that has become empty of affection and riddled with guilt; and a man's need to open himself to love, which will enable him to overcome a life full of severe repression."
Hitchcock the raconteur positioned it in terms of classic conflict. He told Truffaut that
The story of Notorious is the old conflict between love and duty. Cary Grant's job—and it's rather an ironic situation—is to push Ingrid Bergman into Claude Rains's bed. One can hardly blame him for seeming bitter throughout the story, whereas Claude Rains is a rather appealing figure, both because his confidence is being betrayed and because his love for Ingrid Bergman is probably deeper than Cary Grant's. All of these elements of psychological drama have been woven into the spy story.
Sullivan writes that Devlin sets up Alicia as sexual bait, refuses to take any responsibility for his role, then feels devastated when she does a superb job. Alicia finds herself coldly manipulated by the man she loves, sees her notorious behavior exploited for political purposes, then fears abandonment by the lover who put her in the excruciating predicament of spying on her late father's Nazi colleague by sleeping with him—a man who genuinely loves her, perhaps more than Devlin does. Alex is Hitchcock's most painfully sympathetic villain, driven by his profound jealousy and rage—not to mention his enthrallment to an emasculating mother—culminating in an abrupt, absolute imperative to kill the love of his life.
Hitchcock's own mother had died in September 1942, and Notorious is the first time he addresses his mother issues head-on. "In Notorious the role of mother is at last fully introduced and examined. No longer relegated to mere conversation, she appears here as a major character in a Hitchcock picture, and all at once—as later, through Psycho, The Birds and Marnie—Hitchcock began to make the mother figure a personal repository of his anger, guilt, resentment, and a sad yearning." At the same time, he blurred mother-love with erotic love and poignantly, in both the film and in its director's life, "both kinds of love were in fact limited to longing and fantasy and unfulfilled expectations."
The theme of drinking weaves its way through the film from beginning to end: for Alicia it is an escape from guilt and pain, or even downright poisonous. When a guest at the opening party tells her she has had enough, she scoffs: "The important drinking hasn't started yet." She camouflages emotional rejection with whiskey, at the opening party, the outdoor cafe in Rio, the apartment in Rio, then drinking becomes even more dangerous as the Sebastians administer their poison through Alicia's coffee. Even the MacGuffin comes packaged in a wine bottle. "All the drinking is valueless and finally dangerous."
Coming as it did on the heels of World War II, the theme of patriotism—and the limits thereof—make it "astonishing that the movie was produced at all (and that it was such an immediate success), since it contains such blunt dialogue about government-sponsored prostitution: the sexual blackmail is the idea of American intelligence agents, who are blithely willing to exploit a woman (and even to let her die) to serve their own ends. The depiction of the moral murkiness of American officials was unprecedented in Hollywood—especially in 1945, when the Allied victory ushered in an era of understandable but ultimately dangerous chauvinism in American life."