The first time I watched Rear Window, I was 14 or 15 and living in a remote part of Ireland. There was a mile and several hills between us and our nearest neighbours, so the concept of looking out the window and being able to closely survey the lives of an entire community was alien to me, and totally fascinating. I was nurturing an ambition to visit New York at the time and Rear Window, more than any other film I'd seen, gave me a powerful sense of that city's atmosphere: noisy, breathless, intoxicating – even though the whole thing was filmed inside a Hollywood studio.
It's a sweltering New York summer and James Stewart, playing a restless magazine photographer, is cooped up in his West Village apartment with his leg in a cast. The humid air is filled with languorous music: versions of hits by Dean Martin and Nat King Cole, fragments of Bernstein. Everyday domestic dramas unfold in the box-like living spaces across the courtyard and Stewart is their captive audience. Two details I vividly remember from that first viewing: the middle-aged couple sleeping outside on their balcony and frantically trying to save their mattress when it starts pouring rain; and the tip of Lars Thorwald's cigar glowing red in the darkness of his living room after the neighbours' dog is found strangled in the garden.
When I watched Rear Window again at university, I was able to appreciate what the film was saying about the cinema-going experience – of sitting in a dark room and gazing into other people's private lives. "We've become a nation of peeping toms," complains Thelma Ritter, Stewart's nurse and the film's ostensible voice of sanity, when she sees her patient glued to the window in the opening scenes. But before long she's just as transfixed as he is.
If the film was critical of voyeuristic behaviour, Stewart and his co-conspirators would be proved wrong in their suspicions of Lars Thorwald at the climax, after they'd blundered into his life and destroyed his reputation. But this is Hitchcock, connoisseur of the perverse, and the film ended up saying the opposite of what I thought it should. Voyeurism has its rewards; keep a close eye on your neighbours and you might just root out a murderer.
Watching Rear Window recently, I realised Stewart's voyeurism yielded another reward. What stood out for me this time was the film's panoramic view of romantic attachment and its pitfalls. What Stewart is really observing, in his multi-channel display of neighbourhood life, is marriage in its various stages and possibilities: the excited newlyweds pulling down the blinds in their new apartment; the bickering older couple who can no longer conceal their loathing for one another.
Stewart, of course, is in the rather unlikely position of being hotly pursued by Grace Kelly and is – even more implausibly, though the screenplay does a good job of making us believe it – dubious about the merits of shacking up with her. He is the rugged, nomadic type who views marriage as an extension of the cast on his leg; she is a Park Avenue socialite who seems ill-adapted to the one-suitcase life of adventure. It's only by confronting the worst-case scenario of married life – uxoricide, followed by the distribution of spousal body parts up and down the East River – that Stewart can reconcile himself to the idea of settling down. Marrying Grace Kelly might be a drag but it couldn't possibly be as bad as that.
What's extraordinary, for a film that works on these different levels, is that it also manages to be a riveting thriller. The murder scene, which you can only appreciate as such on a second viewing, is a masterpiece of suggestion and ellipsis. In contrast to the in-your-face killings in Hitchcock's Psycho, six years later, this murder happens out of sight, behind lowered blinds. The scream almost goes unnoticed in the New York night and in the bloody aftermath not a drop of blood is seen. The rain falls, Thorwald shuttles in and out of his apartment carrying his silver-coloured salesman's suitcase and we are left to imagine what, exactly, it contains.
Then there is the scene of perfect suspense when Kelly's character steals into Thorwald's apartment while he's momentarily out. Powerless to intercede, Stewart can only look on with mounting anxiety and implore her in a strangled whisper to "Get out of there", like a jumpy audience member in a horror film, when he knows that the murderer will be returning any second.
Hitchcock made a career out of indulging our voyeuristic tendencies and he understood, better than any other film-maker, how to excite them. I don't think he ever did it more skilfully, or with more gleeful self-awareness, than in Rear Window. I've been keeping a close eye on my neighbours ever since.