An interesting discussion is going on at Slacktivist, talking about the way the Macho Sue myth is used to argue that any kind of political negotiation is tantamount to treasonable appeasement. It's intriguing, and I'd urge you to go and check it out.

It's also got me thinking of something else, to do with fiction rather than politics: the problem of male role models in today's movies.

Men watch the action film, right? Images of masculinity are all over the cinema and always have been - but there's something that stands out. Who, among these male leads, would you actually want to be? Not just for the duration of the adventure, but for your life, for your self, who would you choose to be?

My boyfriend and I were spending last weekend with some married friends, and the two men - both of them decent, unaggressive, masculine people - got into a discussion about how men seem to be presented in current films. There's the ultra-macho action man, typified by 300, a film I never stop hating on - but 300 itself is problematic: the ethos of it is so exaggeratedly macho that it ends up looking thoroughly camp. Slightly less extreme films may look less camp, but they still suffer from a basic problem: very few people in any way resemble Jean-Claude van Damme, any more than they resemble The Incredible Hulk in a green mood. The manhood of such extreme action heroes is so exaggerated that it becomes almost abstract, symbolic, a world of cartoonish absolutism that has no connection to real life. Such films are hardly the place to look for role models.

The other fella, who reads more science fiction than me, commented that there's been a rise of 'strong female characters' in that genre since the 1990s, which can't be bad, but in terms of male role models, it's not uncommon for the men in such set-ups to be goofy sidekicks, again, hardly a great model.

Where are the men, we asked? And then our friend pointed out something interesting: that in the more intelligent action films of late - the Bourne movies, Casino Royale - you have men who are undoubtedly strong, but who are also in some way damaged. A man can be masculine, competent, and capable of winning a fight, but only if the film-makers added in some emotional problems.

And thinking about that, I had a realisation: of course there's a problem. The terms of the discussion are all wrong. Because here's the thing: if you're capable of sustained and repeated violence, you do have something wrong with you. But that's what films present manhood as being.

I'm not talking about boxers or martial artists, to be clear; I'm talking about people who can use lethal force. Most people can't. It's not because they're weak, it's because normal people have a strong aversion to killing members of their own species. Studies have found that, without strong conditioning, soldiers have a time-honoured, secret custom of firing into the air, each probably convinced that his comrades are firing at the enemy, but each, whatever his intentions, finding himself simply unable to pull the trigger and send a bullet into a living man. Lt. Col. Dave Grossman in his valuable book On Killing remarks that there are four reactions under stress: fight, flight, posture and submit - and that the vast majority of people prefer to posture than to fight. You fire your gun and make a lot of noise, or you wave your spear and yell, or you deliver non-injurious shoves to the shoulders saying, 'Yeah? Yeah? Come on then, come on!' ... and basically you crack antlers, establish dominance, and the issue is settled without anybody getting badly hurt. Grossman remarks:

That the average man will not kill even at the risk of all he holds dear has been largely ignored by those who attempt to understand the psychological and social pressures of the battlefield. Looking another human being in the eye, making an independent decision to kill him, and watching as he dies due to your action combine to form the single most basic, important, primal, and potentially traumatic occurrence of war.

After all, he points out, battlefield surgeons are often in just as much danger as the soldiers, yet soldiers suffer much greater psychological injury from the stress of battle. The only difference is this: the surgeons are not expected to kill. They may be expected to die, but the risk of death seems to be easier to heal from than the risk of becoming a killer. The sudden, compelling resistance in your trigger finger is an almost universal trait, and you break it at your peril.

There are exceptions. But they're not happy exceptions. Some people can kill without trauma: these are sociopaths. There's something profoundly wrong with their empathy, their ability to feel emotions, their capacity for consideration or remorse. And there are others, too, who are able to kill, to fight rather than posture, under pressure. People fond of that lousy dogs-wolf-sheep analogy regard them as the dogs protecting sheep from wolves (in a battlefield, if you think about it, the odds are that you have dogs fighting dogs while the political wolves slink around the edges, ready to pick over the carcasses); others refer to them as 'warriors'. An oft-cited example is the much-decorated veteran Audie Murphy, who famously answered the question of how he found the courage to fight an entire company of German infantry by the simple statement: 'They were killing my friends'.

But, though Murphy went on to a career as a movie star and public hero, he was not a happy man. In Stiffed, Susan Faludi describes his perpetual inability to settle to peace, searching the streets for thugs he could beat up, sleeping with a gun under his pillow, plagued with insomnia and nightmares, and struggling with feelings a hero wasn't supposed to express:

He wrote that he had 'shed the idea that human life is sacred.' Finding himself in the ruins of the Riviera on the day of Germany's surrender, Murphy recalled his mood among the revelers. 'In the streets, crowded with merrymakers, I feel only a vague irritation,' he wrote. 'There is VE-Day without, but no peace within. Like a horror film run backwards, images of the war flicker through my brain ... It is as though a fire had roared through this human house, leaving only the charred hulk of something that once was green. Within a couple of hours, I have had enough. I return to my room. But I cannot sleep. My mind still whirls. When I was a child, I was told that men were branded by war. Has the brand been put on me? Have the years of blood and ruin stripped me of all decency? Of all belief?'

Murphy himself said that the 'nasty business' of war was 'not the sort of job that a man should get a medal for. I'll tell you what bothers me. What if my sons try to live up to my image? What if people expect it of them?'

Audie Murphy was brave, self-aware and intelligent - but there was something wrong with him, and he knew it: he was capable of violence. This is the problem with male action heroes we face today. What in reality is a flaw, a crack in the ice that may only harm others in the case of a psychopath, but will harm the hero as well if he has any virtues, is being presented as the essential quality of manhood.

But where are the alternatives? A favourite hero of my boyfriend's, and mine as well, is Juror Number Eight, the man in the white suit, played by Peter Fonda in 12 Angry Men. This man - Davis by name, as we learn at the end - is unquestionably masculine. The references to his personal life are scant but successful: he's an architect, a profession both artistic and technical, with three children - not merely two, like many couples, but a slightly above-average fertility. Davis is fairly ordinary, even down to his name, but at the same time, he's heroic. 'This man has been standing alone', a sympathetic fellow-juror remarks, naming the quality of heroes everywhere. But Davis's virtues are about moral and intellectual strength, not physical. He keeps control of his temper, he forges relationships with others in the room, he holds to his principles, he strives for fairness, he works out the logic of the case and encourages others to do likewise, and what he ends up saving, in microcosm, is the whole ideal of justice. Notably, we never find out if the boy he saves from the chair actually did commit the murder, and that isn't the point. It's not about being right, it's about trying to fulfil your civic duty. As another juror says, 'You can't send a man off to die on evidence like that!', and that's the point: you may or may not be right, but as long as you're not sure, you hold to the principle of innocent until proven guilty, and thus civilisation stands.

Davis, in fact, is entirely free of violence - the jurors who get angry and show violent feelings are presented as wrong, not just disagreeable but neglectful of their civic duty because they can't control a personal mean streak. It's only by avoiding conflict that the issues gets solved. Davis is a maintainer, not a frontiersman, and offers the kind of heroism that a reasonable person may aspire to.

Realistically, most people don't get into fights very often. There are all sorts of masculine virtues that don't involve violence - most of them virtues women can have as well, but nobody rational considers that men and women are such opposites that no quality can be possessed by both sexes. Decency, patience, self-control, stability, competence, integrity, creativity, stamina, honesty ... these are all qualities that daily life calls for far more often than the ability to win a punch-up or fire a weapon. And they're all qualities far more likely to lead to the kind of lives that most men actually want.

But we can't quite get past that violence. Dan Kindlon and Michael Thompson remark in Raising Cain: 'Popular movies aimed at boys seem to prize only one kind of courage: standing up to a physically larger opponent.' This is why He was a man of peace ... until they came for his family! is such a compelling storyline. Most men are not naturally violent, and don't really want to fight anyone. What they are good at is loving their families, because men are people and people do love their families, and a man who's a good husband and father makes a tremendous contribution to the happiness of the world. But at the same time, men are supposed to be fighters. So a gentle man may end up saying to himself, 'What would I actually be prepared to fight for? Well, I guess if someone threatened my wife and kids...' The Man of Vengeful Peace is someone whose life resembles the majority of his audience's at the beginning of the story, but who is given a set of circumstances that, however improbable, push him into acting like the template action hero that the men of the audience do not, cannot, need not resemble.

But where are the men who make things? Where are the men who teach, or guide, or innovate, or improve? Not in the action movies, that's for sure - and that's the only genre particularly aimed at men. Romance is the genre aimed at women, and many women enjoy a good love story just as much as many men enjoy a good high-octane thriller - but women tired long ago of being offered no other heroic role than that of the swooning, rescued bride. The romance heroine by herself is not a malign figure if she's done well, any more than the physically brave hero is inherently wrong if he's done well, but it insults and stifles an entire sex to be presented with only one model of heroism. All of us deserve better.

And the world needs better. We find killing difficult, On Killing explains, but there are degrees of difficulty. Killing a man with your bare hands is harder than killing a man a knife's distance away from you, is harder than killing a man at bayonet range, is harder than killing a man the distance of a bullet away, is harder than pressing a button and dropping bombs onto an undistinguished blur of houses below. If we measure manhood in willingness to kill, but most men are not killers, what are we going to do? There are two choices. Either we must redefine our notions of manhood, recognising the virtue of the man who quails to kill his brother, or we must find ways of preserving the fantasy. To preserve the fantasy, we need killings, to prove that we have men who performed them. And how to do that? Training that overrides the soldier's natural hesitation is now a common part of the army, but you cannot train out the trauma that follows. The rate of suicide in army veterans currently stands at the highest figure in nearly three decades of record-keeping, and a third of Iraq and Afghanistan veterans - over thirty thousand souls - are suffering from some kind of mental illness. The lists of the psychologically wounded are rising, men and women who did things they were never born to do. And what's the other solution? Engineer situations in which killing is as easy as possible. A bomb dropped from a plane may cause less hesitation in the pilot, but it kills a lot of people below.

It's time to separate manhood from violence. It insults men, and endangers us all.