The morning after the latest mass shooting on American soil, I went to a street festival in my adopted home town of Cambridge, Massachusetts. The sun was out. Brass bands were playing. Children were mainlining sweets and charging about in a frenzy of high-fructose corn syrup. You would not have thought that their country was in the grip of an epidemic of attacks by murderous fanatics on schools, hospitals and universities.

As I write, the shooting of four people at a college in Flagstaff, Arizona, is the most recent gun attack to make the headlines in the US. One student died. It’s no exaggeration to say that by the time this piece is published, there may have been another. The previous attack, which took place in Oregon and left ten dead, was eight days earlier. This week, a YouGov study showed that 35 per cent of Americans think mass shootings are “a fact of life”.

The US has more mass shootings than any other nation in the world – five times as many as the Philippines, the next country to top that ignominious roll call. In America, they have become a meme, an idea with a life of its own that spreads like a virus wherever the conditions are right. In this case, the conditions are anger, entitlement, a background thrum of violence and easy access to firearms. Deaths in the US from gun violence, as Barack Obama pointed out in one of many such condolence speeches he has made during his time in office, enormously outnumber deaths from officially designated terrorist acts. “We spend over $1trn and pass countless laws and devote entire agencies to preventing terrorist attacks on our soil, and rightfully so,” he said. “And yet we have a Congress that explicitly blocks us from even collecting data on how we could potentially reduce gun deaths.”

This says more than Americans might wish to understand about the political priorities of their nation. Many of the same Americans who clutch their guns tighter after every new massacre will line up to forgo their civil rights at the first whisper of foreign terrorism. But violence committed by white American men is normal and natural, even at its bloodiest extremes. It cannot be terrorism, even if it is designed to produce terror, because it is not a threat to the social order.

Mass violence only gets to be terrorism when it is committed by cultural outsiders. Two years ago, my adopted hometown disintegrated into collective panic after two young men murdered three people with home-made explosives at the Boston marathon, just across the river. The entire metropolitan area was put under curfew as the man-hunt for the Tsarnaev brothers went on. The city was descended into a frenzy of fear that has yet to dissipate. T-shirts are still available in tourist shops and convenience stores bearing the legend “Boston Strong”, the rallying slogan used by Bostonites to declare that they would not be broken. Meanwhile, the reaction of the American public to the 35 mass shootings since 2005 has been one of sorrow – but not shock, and certainly not alarm.

There is a reason for that, and it is an ugly one. To many Americans, the Boston Bombers were following a different cultural script. They were foreigners. Muslim foreigners, at that. When a young Muslim man commits mass murder, he is a terrorist, a threat to the entire nation. When a young white man does the same . . . in the words of Jeb Bush: “Stuff happens.”

Killers who aren’t white men are usually described as terrorists, no matter how bonkers their manifesto, if they have one. Mass murder, in fact, is the one situation in which people from ethnic minorities can count on being treated seriously as political agents. A white man who commits mass murder, by contrast, can write a detailed, grammatically coherent manifesto, distribute it ahead of time, explaining precisely why he picked his victims and what statement he was hoping to make – and commentators will fall over themselves to dislocate his crimes from any possible political context, will insist that these are isolated acts of individual disturbance, will twist themselves into discursive knots to avoid stating the obvious. Malcolm Gladwell, writing in the New Yorker this week, opines that “the great puzzle is how little school shooters fit any kind of pattern”.

But there is a pattern. There is a clear pattern. More than 98 per cent of mass murders in the United States are committed by men. Most of them are young, most of them are frustrated and almost all of them are white. But when the overwhelming maleness of mass shootings is raised, the explanations sound an awful lot like excuses. It’s the effect of testosterone on the brain. It’s video games. It’s just the way boys are. It’s just the way men break. Women collapse inwards – men explode outwards, and sometimes they take A good few others with them. These young men are mad, and that’s the end of the matter. When Dylan Roof murdered nine people at a historically black church in South Carolina earlier this year, Republican representative Sanford appeared on CNN to say:

“I don’t know what was going through the kid’s mind, but [it’s] certainly the act of a deranged human being, and this level of malice I think is unfathomable in this community, in this nation.”

To call Dylan Roof insane is to miss the point. To declare his violence unfathomable is deliberately to avoid the point. Most people who have reached the stage of contemplating such carnage are at least ethically deranged. But madness is also a political category, a taxonomic dumping ground for any behaviour that society doesn’t want to deal with. And the things the US doesn’t want to deal with right now are toxic masculinity, misogyny and racism.

The murderous ritual violence of young white men is political. The blogs and public posts of Elliott Rodger, Dylan Roof and Adam Lanza are steeped in the language of racism and misogyny, drenched in the conviction that they had been cheated of their birthright by women, people of colour or both, and. Their violence is political, and so is the tacit agreement by the American public that it is not political, must not be comprehended and will not be comprehended.

Why does this matter to non-Americans? It clearly does matter, because every time a gunman lets rip in a college, a school or a church in the United States, it makes headlines across the world. It matters because America is still looked to to provide ethical leadership. It matters because the moral foundation of American power is its claim to uphold standards of freedom and justice - and to export them by force, if necessary. The ongoing meme of mass gun violence in America is not simply tragic. It is not simply embarrassing. It is a political statement in itself.

My American friends are invariably stunned when I tell them that in Britain it took just one school tragedy – the Dunblane massacre of 1996 – to persuade politicians and the public to institute a ban on private handgun ownership on the mainland, giving us some of the toughest firearms legislation in the world.

I’m not claiming that Britain is a politically reasonable or humane place. We do, after all, have a queen, an ancient and arcane parliamentary system where bigots and aristocrats bellow at each other like howler monkeys over how quickly to strip welfare from the poor, a surveillance apparatus the Stasi could only dream of, and Boris Johnson. But since the institution of gun control, the murder rate in Britain has fallen. Experts can only guess as to how much of an effect gun control has had in the UK, just as they can only guess the potential impact in the USA, but the issue is not just about gun control. It’s about what gun control represents: namely, the collective will to do something to turn the tide of violence.

American conservatives are prepared to sacrifice any number of constitutional and human rights in the name of protecting themselves from the real or notional violence of young Black and Muslim citizens. But after each US school shooting, as politicians, pundits and private citizens rally against gun control with the same breath they use to express condolences to the victims, they send the message that nothing can be done and nothing should be done. They send the message that this is tolerable.

And one can tell a great deal about a society by the kinds of violence it is prepared to tolerate.

While young white men commit mass murder in increasing numbers, it is young black and Muslim men who are stopped and frisked on every street corner, gunned down for looking the wrong way at traffic cops and imprisoned in their hundreds of thousands. The failure of the US to discipline the violence of young white men is as much of a political statement as the excessive discipline it imposes on the bodies of young black citizens.

In the face of the murderous frustration felt by a minority of young white men, in the face of their viral, vengeful fury at being denied privileges they have always been told were owed to them, the US has thrown up its hands and said: these things happen. It’s tragic, of course, but it’s tragic in the way that a tornado or an earthquake is tragic.

It’s just nature. Nothing can be done.

Something can be done, however, and something must be done. Something must be done to challenge the social attitudes that condone these shootings. Something must be done, in the US and beyond, to challenge the everyday violence of toxic masculinity that has become so normalised that it is culturally invisible. And that’s not just about school shootings. It’s about rape culture on campus. It’s about the vicious harassment of any woman who dares to raise her voice online. It’s about domestic violence. It’s about a culture that accepts all of these things as “natural”. A culture that looks at the carnage and says: well, boys will be boys.

How do you stop a meme? By changing the cultural climate in which it spreads. As a foreigner from a nation with its own political psychoses, my opinions count for less – but here’s my suggestion.

Given that the one single quality that almost all mass murders have in common is gender, and given that when women use firearms, they generally do so in self-defence, a decent interim solution might be to impose a year-long waiting period on gun ownership – but only for men. Let the women and gender-variant people have all the guns they want right away. If that sounds like a ludicrous piece of political positioning, well, it’s no more ludicrous than declaring these ritual massacres a “fact of life” – and no less political.