A few years ago, the British found their own threshold— with guns—after an event not unlike the heartbreaking tragedy in Newtown, Connecticut. On March 13, 1995, in the small Scottish town of Dunblane, a forty-three-year-old man, Thomas Hamilton walked into a primary school with four handguns and opened fire, methodically killing sixteen children and one adult teacher before killing himself. The unprecedented massacre of children led, within two years, to legislation that imposed a total ban on the private ownership of handguns in the United Kingdom. Today, no one in the United Kingdom can privately own a handgun or a semiautomatic weapon. (There are exceptions made for some historic and antique weapons, and the ban does not encompass Northern Ireland.) There was not much hand wringing or heated debate over this legislation. It was discussed, and enacted, with overwhelming public support, in response to the mood of national shame and grief over the killings.

There is still violence in Britain. In recent years, there has been a disquieting upsurge of violence amongst teen-agers in large British cities. Much of it is gang related, and almost all of it involves knives. Knives are not hard to obtain, but kill far fewer people than guns do. After the movie-theatre shooting in Aurora, Colorado, the Guardian did the math, comparing gun homicides in the U.S. to England and Wales in one year: 9,146 to forty-one. Even taking into account the difference in population, the rates of gun homicide per a hundred thousand people are 2.97 versus .07.

In China, where private gun ownership is also banned, but where social alienation is clearly becoming a larger problem, there have been a distressing number of recent attacks by deranged knife-wielding men on schoolchildren. On Friday, in fact, as Evan Osnos writes, in an incident with uncanny similarities to the Newtown massacre, a young man walked into the Chenpeng Village Primary School near the city of Xinyang, south of Beijing, and attacked the schoolchildren with a knife as they arrived at school. Twenty-two children were injured before the assailant, said to be a thirty-four-year-old man, was subdued and arrested by police—but there were no deaths. If he had been using a gun, the likelihood is that most of those children would now be dead.

A heated debate on new gun-control legislation has been sparked off by the Sandy Hook massacre. But if past patterns are anything to go by, it’s unlikely that anything will change yet in the United States. What will it require for a majority of Americans to realize that they have a national problem that needs to be urgently addressed? We have lost four Presidents to gunmen in our short history as a nation, and very nearly lost several more. Last year, Arizona Congresswoman Gabrielle Gifford’s promising political career was cut short by a gunman who shot her in the head, killed six others and wounded thirteen more. Gifford spends her days now in therapy attempting to recover basic abilities like speech and eyesight, both of which were severely affected by her wounds.

But Americans seem to take the shooting of their politicians in stride. Would even another, much larger school massacre bring about change? If the numbers are on a truly epic scale—an American scale—perhaps enough people will finally say “enough.” If someone murdered a hundred schoolchildren in a single day with guns, would a majority of Americans agree to true restrictions on them? What is our national threshold for shame?