''I have always believed that a man can love and respect another man more so than he can a woman," said Borden Chase, screenwriter of such classic westerns as Red River (1948), Winchester '73 (1950) and The Far Country (1954). Like most examples of the genre, Chase's movies tend to portray men spending far more time with each other than with women; heterosexual love is depicted only perfunctorily. From poker games in Gold Rush saloon bars to cattle drives, the narrative territory of the American West has been overridingly male.
Underpinning this vision has been an apparent confidence that male companionship will remain non-sexual. In Ang Lee's new film, Brokeback Mountain, however, this assurance is questioned. Based on Annie Proulx's short story, the film depicts the love affair between a rodeo rider and a ranch hand in 1960s Wyoming. Hired to herd sheep for a summer on an isolated mountain, the men become lovers. They inhabit a society that regards homosexual love as taboo, and when they return from the mountain they struggle to continue their relationship. Though they sporadically rekindle their passion, they spend the rest of their lives consumed by longing for their summer on Brokeback Mountain.
In its overt portrayal of male sexual love, Brokeback Mountain appears to be a dramatic departure from earlier westerns. But is this really so? The western is a diverse genre - Martin Scorsese has spoken of its "perverse variations" - and it has accommodated a range of attitudes towards masculinity and sexuality. A few early films, such as The Outlaw (1943) and The Big Sky (1952), flirted unanxiously with the idea that homosexuality can be fun (and need not rule out fun with women), though they had to tread carefully around Hollywood censorship. By the end of the 1960s, Midnight Cowboy and Andy Warhol's Lonesome Cowboys (both 1969) were playing with the homoerotic allure of the cowboy image.
Yet classic westerns are laments for a pioneering spirit that becomes increasingly irrelevant as frontier life gives way to more settled communities. They often have an elegiac tone, and portray an old nobility of cowboy pioneer-warriors who are destined to become as obsolete as the hunters who preceded them. Sam Peckinpah's films, for instance, nearly all buy into an American myth in which tough male individualism is doomed by the effeminate, corrupt metropolitan world.
The best westerns, however, have always implicitly been anti-westerns as well: thoughtfully ambivalent about violence, and aware how little may separate an ideal masculine prowess from brutality and racism. Such films have been less nostalgic for the old pioneer spirit, instead welcoming the more fluid idea of masculinity that replaced it.
In Howard Hawks's great epic Red River, John Wayne, as the trailblazing cattle-driver Tom Dunson, turns into a kind of tyrannical Captain Bligh. His adopted son Matt (Montgomery Clift) plays the Fletcher Christian role (very glamorously), and the film seems destined for a tragic ending until the plot takes a happy final turn. Set just after the civil war, Red River suggests an idea of generational change in which Monty Clift succeeds John Wayne. The implication is that the authoritarian, unyielding American patriarch will inevitably give way to a softer kind of male protagonist.
Brokeback Mountain is the heir to this more reflective tradition. Proulx's original story, like much gay fiction, imagines a beautiful, idealised landscape in which taboo love can breathe. On Brokeback Mountain the lovers Ennis and Jack (played by Heath Ledger and Jake Gyllenhaal) are "suspended above ordinary affairs" (though not, it turns out, beyond the gaze of unfriendly binoculars).
The film breaks ground in showing modern, working-class, gay characters in the American West trying to make a life together. Proulx's mountain reminds me of the New Mexican mesa where Tom Outland and Roddy Blake live amorously for a season in Willa Cather's novel The Professor's House (1925). Cather's fictions imagine a real if compromised place for all sorts of outsiders, racial and sexual, in pioneering America; but in Brokeback Mountain there is simply no place for Jack and Ennis to continue their love, in the Wyoming of their time.
And not just their time: Proulx's short story was published in 1997, the year before the student Matthew Shepard was murdered in Wyoming in a homophobic hate crime. But though the film evokes homophobia as immutable and murderous, it has a liberalising charge. Its appearance does a kind of honour to the martyrs and pioneers of rural gay America.
Brokeback Mountain is released on 30 December. Peter Swaab is writing a book about ideas of utopia in gay and lesbian literature