The firearms massacres that have periodically caused shock and horror around the world have been dwarfed by the Mumbai shootings, in which a handful of gunmen left some 500 people killed or wounded.

For anybody who still believed in it, the Mumbai shootings exposed the myth of “gun control”. India had some of the strictest firearms laws in the world, going back to the Indian Arms Act of 1878, by which Britain had sought to prevent a recurrence of the Indian Mutiny.

The guns used in last week’s Bombay massacre were all “prohibited weapons” under Indian law, just as they are in Britain. In this country we have seen the irrelevance of such bans (handgun crime, for instance, doubled here within five years of the prohibition of legal pistol ownership), but the largely drug-related nature of most extreme violence here has left most of us with a sheltered awareness of the threat. We have not yet faced a determined and broad-based attack.

The Mumbai massacre also exposed the myth that arming the police force guarantees security. Sebastian D’Souza, a picture editor on the Mumbai Mirror who took some of the dramatic pictures of the assault on the Chhatrapati Shivaji railway station, was angered to find India’s armed police taking cover and apparently failing to engage the gunmen.

In Britain we might recall the prolonged failure of armed police to contain the Hungerford killer, whose rampage lasted more than four hours, and who in the end shot himself. In Dunblane, too, it was the killer who ended his own life: even at best, police response is almost always belated when gunmen are on the loose. One might think, too, of the McDonald’s massacre in San Ysidro, California, in 1984, where the Swat team waited for their leader (who was held up in a traffic jam) while 21 unarmed diners were murdered.

Rhetoric about standing firm against terrorists aside, in Britain we have no more legal deterrent to prevent an armed assault than did the people of Mumbai, and individually we would be just as helpless as victims. The Mumbai massacre could happen in London tomorrow; but probably it could not have happened to Londoners 100 years ago.

In January 1909 two such anarchists, lately come from an attempt to blow up the president of France, tried to commit a robbery in north London, armed with automatic pistols. Edwardian Londoners, however, shot back – and the anarchists were pursued through the streets by a spontaneous hue-and-cry. The police, who could not find the key to their own gun cupboard, borrowed at least four pistols from passers-by, while other citizens armed with revolvers and shotguns preferred to use their weapons themselves to bring the assailants down.

Today we are probably more shocked at the idea of so many ordinary Londoners carrying guns in the street than we are at the idea of an armed robbery. But the world of Conan Doyle’s Dr Watson, pocketing his revolver before he walked the London streets, was real. The arming of the populace guaranteed rather than disturbed the peace.

That armed England existed within living memory; but it is now so alien to our expectations that it has become a foreign country. Our image of an armed society is conditioned instead by America: or by what we imagine we know about America. It is a skewed image, because (despite the Second Amendment) until recently in much of the US it has been illegal to bear arms outside the home or workplace; and therefore only people willing to defy the law have carried weapons.

In the past two decades the enactment of “right to carry” legislation in the majority of states, and the issue of permits for the carrying of concealed firearms to citizens of good repute, has brought a radical change. Opponents of the right to bear arms predicted that right to carry would cause blood to flow in the streets, but the reverse has been true: violent crime in America has plummeted.

There are exceptions: Virginia Tech, the site of the 2007 massacre of 32 people, was one local “gun-free zone” that forbade the bearing of arms even to those with a licence to carry.

In Britain we are not yet ready to recall the final liberty of the subject listed by William Blackstone in his Commentaries on the Laws of England as underpinning all others: “The right of having and using arms for self-preservation and defence.” We would still not be ready to do so were the Mumbai massacre to happen in London tomorrow.

“Among the many misdeeds of British rule in India,” Mahatma Gandhi said, “history will look upon the act depriving a whole nation of arms as the blackest.” The Mumbai massacre is a bitter postscript to Gandhi’s comment. D’Souza now laments his own helplessness in the face of the killers: “I only wish I had had a gun rather than a camera.”

Richard Munday is the co-author and editor of Guns & Violence: The Debate Before Lord Cullen