How so? ''It's their guns. They are crazy about their guns. You can just walk into a Walmart here and buy a hand gun for $50.'' It's one of America's distinguishing characteristics. Today, we see the American love of guns leading it to tolerate the intolerable. In reaction to the premeditated murder of 12 people and malicious wounding of 59 by one citizen in a Denver cinema, we hear the country's President call it ''terrible'' and the opposition candidate for the presidency call it ''hateful.'' What we hear neither man call it is ''preventable''. Yet it must be, or at least the incidence of mass shootings must be subject to some sort of management. Consider Canada. The US and Canada are both new nations, both former British colonies, both frontier societies, thoroughly interconnected across the longest border in the world. Their murder rates have moved up and down in close sync with each other for 60 years now. But here's the rub - Canada's moves in parallel with America's, but at a much lower level. Canadians kill each other at less than one-third the rate.

Gun control must be at least a partial answer. To the world outside the US, it seems commonsense. Societies cannot prevent people going on rampages, but we can minimise the harm by restricting access to the most murderous weapons. Whenever I hear news of a schoolyard stabbing in Australia, I find myself wondering how it might have played out if guns were as readily available here as in the US. The familiar catchcry of America's gun lobbyists is ''guns don't kill people, people kill people.'' But guns are a force multiplier for the same murderous impulses. This was the logic of John Howard's clampdown on gun ownership after the Port Arthur massacre in 1996. Australia's murder rate in 2010 was 1.2 per 100,000 head of population. America's? Exactly four times as great, at 4.8. No country will ever prevent every such atrocity. Last year's mass murder in Norway is an example. Guns are in plentiful supply in Norway, a country of hunters, but closely regulated. Yet Breivik was able to assemble his collection of explosives, guns and bullets regardless. But some commonsense regulation is a necessary condition for minimising harm, surely? In the US today, prevention of mass murders by arms control is a lost cause. Mass murder is now so routine in the US that is almost background noise.

''In our country, the mass shootings come so frequently that most of them go by virtually unnoticed,'' Gail Collins wrote in The New York Times. ''Did you catch the one last week in Tuscaloosa? Seventeen people at a bar, hit by a gunman with an assault weapon.'' The answer, of course, for almost everyone, is no. A recent school shooting with multiple deaths rated third-story status in the national TV news and disappeared without trace in a single news cycle. It takes a spectacular outrage or a novel one to get top-line national attention, and the James Holmes massacre was both. Even the most basic commonsense prudence is now an unacceptable violation of an American's right to bear arms. When the Attorney-General asked for the power to prevent people on the terrorist watch list from buying guns, the US Congress answered with a firm ''no''. The US is not just crazy about guns, its people are also much readier to kill by any means possible. Even if you subtract from the US murder count all the killings committed with knives, baseball bats, rope, candlesticks and so on, Americans still commit murder at a higher rate than Europeans. So the US grapples with a combination of more murderousness, as well as a readier supply of the force multiplier of guns, including high-powered ones. Why? The answer is in its history and geography. The contrast with Canada is instructive. In the US, the pioneers went first and law enforcement followed. In Canada, the Mounties arrived with or before the first settlers. The frontier was never lawless. The state, with its monopoly on violence, was the foundation. In America, the foundation was violence as a private right - especially in the frontier territories.

Indeed, when it comes to violence, the contrast between the south and west on the one hand and the north and east is so stark that it is as if they were two different countries, as Steven Pinker has pointed out in his history of violence, The Better Angels of Our Nature. He speaks of a ''ribbon of peaceable states'' across the north ''at the top of a gradient of increasing homicide from north to south.'' The ribbon follows the path of the immigrants who first landed in peaceful New England, bringing European levels of violence with them. And the other central fact of US geography is that the country's population, and its politics, have been moving inexorably to the south and the west for decades. In fact, the US Census Bureau's measured centre of population gravity moves south-west at a steady 90 centimetres a year. America's gun craze can look ugly to people more accustomed to more lightly armed European sensibilities. But it's striking to observe that the US, unlike Europe, has never proven fertile ground for a fascist political movement. There was wisdom in my former neighbour's philosophical acceptance of America and its foibles, good and bad. Loading

Peter Hartcher is the international editor. Follow the National Times on Twitter