Identity (Mistaken vs. Authentic)
The main theme of North by Northwest is identity, or more specifically in this case, mistaken identity. The various struggles Roger Thornhilll faces to clear his name and discover the truth makes the viewer consider the permeability and fragility of identity.
At the beginning of the film, Roger is misidentified as Kaplan simply because he appears to respond to Kaplan’s name in the lobby of the Plaza. A simple misinterpretation of events by two violent thugs set the entire plot in motion. An everyday misunderstanding leads to a much larger and more dangerous misunderstanding, as Thornhill spends much of the rest of the movie trying to prove his true identity. All of his efforts to deny that he is Kaplan simply reaffirm to the villains that he is in fact Kaplan. Vandamm likewise is able to assume the identity of Townsend simply by occupying his house. When the police return the next day to question “Townsend," they find he is not at home, but take the word of his “wife” that he is addressing the general assembly of the United Nations at face value. Vandamm's sister's performance as Mrs. Townsend is enough to convince the authorities that Roger is lying.
Later in the film, Roger is framed for murder because he was seen talking to the real Townsend just as he is stabbed in the back. A photograph with Roger holding the knife is all that is needed to cement his identity as a dangerous assassin in the eyes of the public. In every case, misleading and often erroneous facts establish a misidentification for various characters. Thus, the film establishes that identities are tenuous and arbitrarily defined.
Isolation
Isolation is another prevalent theme in North by Northwest. Roger is isolated by his misidentification, unable to convince those around him of his abduction, and then later unable even to show his face after being framed for the murder of Townsend. Roger’s solitary struggle is heightened by several factors, including his status as a single man, the fact that no one believes him, the ever-present threat of a murderous gang, and later the fact that he is on the cover of every national newspaper holding a knife that had just stabbed a man in the back. As his jeopardy increases, so does his solitude.
This “one man against the world” theme is ever-present, as those who might be of help to Roger either can’t or refuse to. His mother doesn’t believe him, the Professor and the board members refuse to interfere, and Eve is in league with Vandamm.
Hitchcock makes use of certain camera angles to go along with this theme, including a shot taken from far above the United Nations, depicting Roger running alone from the building. There is a similar shot when Roger is waiting for Kaplan on a deserted road. The crop-duster scene also ties in to Roger’s seclusion, as he repeatedly tries and fails to wave for help to passing motorists. The open fields of the Midwest serve as a perfect allegorical playground for his solitude and alienation.
Honesty and Performance
In line with the theme of mistaken identities, honesty becomes central to the plot of the film, as Thornhill soon learns that he cannot trust anyone, and that the truth is constantly slipping away from him. After he is abducted by Vandamm, his honest protestations and insistence that he is not George Kaplan are met dismissively. When he is handed over to the police, his honest insistence that he was abducted is completely dismissed as well. No matter how earnestly Roger Thornhill tells the truth in the film, his honesty is not enough to protect him, and he must instead resort to his wits.
Additionally, the world of intelligence agencies and high-level international crime is, rather predictably, a dishonest affair, and requires the performative expertise of its participants. While Roger Thornhill is an advertising executive, well-versed in the languages of persuasion, he finds himself in a complex web of deception and performance when he enters the orbit of Vandamm, and eventually, Eve. Eve is perhaps the most skilled actor of them all, fluidly switching between her role as Thornhill's confidant and lover, Vandamm's mistress and accomplice, and the Professor's political informant. Acting is a requirement in the mysterious organizations of North by Northwest, and in order to survive, Thornhill must play along to perfection.
Government Secrets
The primary irony of the film is that Roger Thornhill is mistaken for a government agent, when he is in fact just a normal New York advertising executive. The basis on which Vandamm and his clan pursue Roger Thornhill is their belief that he is after them and that he maintains some link to the government. During the time in which the film takes place, America was in a particularly tense and hostile relationship with the Soviet bloc, and so political secrets and international deception loomed large in films and other cultural narratives. While the content of the information that is at stake in North by Northwest remains vague, alluded to through microfilm and mysterious disappearances, the secretive political underworld in which Roger Thornhill finds himself has startlingly high stakes, because of its connection to the dissemination of high-level government secrets. What Thornhill gets accidentally entrenched in is no less than the Cold War itself, a war of backrooms, top-secret information, and constant deception.
Sex
Roger Thornhill is established from the start of the movie as a silver-tongued, reckless playboy, as he gives orders to his secretary to send a box of chocolates to a woman with whom he is having an affair. In his fast-paced world, sex is a negotiation, a matter of a well-wrapped gift and a witty one-liner. When he meets the mysterious Eve Kendall, Roger is disarmed to discover her abilities in matching his erotic frankness. Eve's cool sexuality is her primary attraction for Roger, in addition to her savvy ability to help him in his state of need. Their love affair is, from the start, explicitly sexual, and defined by its passion and wry wit, as much as its mutual affection. Sex is a joke, but a joke that both Eve and Roger take very seriously, as they banter back and forth on their first evening together. Eventually, the movie leaves us with an image of sex, as Roger pulls Eve up onto the bed in a train that propels through a tunnel, a symbolic image that Hitchcock admits was phallically sexual, "probably one of the most impudent shots I ever made."
The American Landscape
As Roger Thornhill becomes embroiled further and further in the complex mystery of his mistaken identity, it takes him all over the country. At the start, viewers find themselves in a bustling mid-century New York City, with businessmen in flannel gray suits hailing cabs and frantic city-dwellers rushing to make the bus. New York is a frenetic metropolis, and Roger Thornhill fits right in, stealing a cab from a man by lying that his secretary is ill, arriving fashionably late to business drinks at the Oak Room, and never ruffling his perfectly pressed suit. Roger Thornhill is the consummate New Yorker, but when he is mistaken for George Kaplan, and then framed for murder, he must leave his comfortable life in the city and embark on a northwesterly tour of the country.
He makes his journey by train, and the viewer sees the gorgeous sunsets of the American countryside. Once in Chicago, Eve deceives him by sending him out to middle of an Indiana cornfield. Here the viewer encounters an iconic shot in American cinema: the American businessman, freshly shaven, hair combed, and suit immaculate, standing on the side of a desolate Midwestern road, waiting to meet a man who doesn't exist. The shots of Roger on the side of the road, and then eventually running from a rogue crop-duster, are evocative and show just what a long way from home Roger truly is, and how diverse the American landscape can be.
Later, the plot takes Roger to Keystone, South Dakota, to the foot, and then the head of Mount Washington, perhaps the most iconically American monument. At the climax of the film, Roger and Eve have no choice but to escape the Vandamm clan by sliding down the side of Mount Washington, running frantically through the faces of the iconic American presidents carved into the side of the mountain. With these shots, Hitchcock and screenwriter Lehman remind the viewer just how iconically American this film is, and how Roger Thornhill represents an American everyman, winding his way through a confusing Cold War intrigue with aloof composure and surprising ingenuity.
Roger's Relationship with his Mother
While the theme is barely developed, Roger's relationship to his mother, her seemingly critical attitude towards her son, and her lack of belief in his dramatic tale of abduction, are important to the viewer's understanding of Roger's situation. At the start of the film, we learn that he is intending to go to the theater with his mother that evening, and tells his secretary to let his mother know that he will have had two martinis at a business meeting before he arrives at dinner. It is implied that Mrs. Thornhill does not approve of Roger's drinking habits, and needs to be reassured before their meeting. When he is forcibly intoxicated by Vandamm's men, then, it becomes clear why Mrs. Thornhill struggles to believe her son's story against the false Mrs. Townsend's insistence that he got very drunk the previous evening. Roger's mother is skeptical of him and does not approve of what she perceives to be his recklessness. Hitchcock isolates Roger in a most Freudian way; even his own mother, when faced with the presence of Valerian and Licht, his attempted assassins, laughs at the idea that he is in mortal danger.
