It took New Zealand just six days to announce an immediate plan to change to the nation’s gun policy after a gunman killed 50 people at two mosques in Christchurch last week.
On Thursday, a day after the first victims were laid to rest, Prime Minister Jacinda Ardern announced a national ban on all military-style semiautomatic weapons, all high-capacity ammunition magazines and all parts that allow weapons to be modified into the kinds of guns used in last week’s attack.
Ms. Ardern is expected to encounter little resistance in Parliament. The new law could be in place as soon as April 11.
It is unclear how the weapons ban will be felt in New Zealand, where there are plenty of guns but relatively few murders. Since 2007, gun homicides have been in the single digits every year except in 2009, when there were 11.
But the swift action already stands in stark contrast to the federal response to mass shootings in the United States, which has the highest rate of gun ownership in the world and is one of only a few countries that start with the assumption that gun ownership is a right, not a privilege.
After a gunman killed 58 people in Las Vegas in 2017, it took 443 days for the United States to ban bump stocks, the attachments that enable semiautomatic rifles to fire in sustained, rapid bursts, which the gunman used in the attack. And after a mass shooting at a high school in Parkland, Fla., last year led to a wave of student activism, the House of Representatives voted to require background checks for all gun purchasers in February. It was the first significant gun control bill to clear the chamber in a quarter of a century, but it was unlikely to even be taken up in the Republican-controlled Senate.
In most countries, mass shootings account for a small proportion of gun deaths. But they are often the political impetus for legislative change that can help prevent other kinds of gun violence, including intimate-partner violence and suicide.
Here is a look at how some other countries took action after mass shootings.
In Australia, guns are a privilege, not a right.
Ms. Ardern said the overhauls planned in New Zealand were partially inspired by changes Australia made after a mass shooting there in 1996.
After gunman with a semiautomatic rifle killed 35 near a popular tourist site in the Tasmanian town of Port Arthur, John Howard, Australia’s conservative prime minister at the time, introduced a federal law to officially make guns a privilege, not a right. Gun owners were forced to provide a valid reason for owning a weapon, such as farming or hunting. Licensing rules were tightened, a 28-day waiting period for gun purchases was imposed and a national gun registry was established.
The overhaul also severely restricted firearms, including a ban on almost all automatic and semiautomatic rifles, as well as shotguns. Australia bought back more than 650,000 firearms, to the resentment of many rural gun owners.
Australia has not had a shooting as deadly as the Port Arthur massacre since 1996. Research shows the country also saw a decline in homicide and suicide after the legislative change, although researchers disagree about whether the ban can be credited for reducing homicides, which had already been declining.
Australia is a much smaller country than the United States and also had fewer barriers to enacting gun control: There is no constitutional right to bear arms, for example, and there are no pro-gun lobbying groups the influence of the National Rifle Association.
After a school shooting, Britain effectively banned handguns.
In 1987, a gunman in the southern English town of Hungerford killed 16 people, leading to tough British laws that required shotgun owners to register their weapons and prohibited semiautomatic weapons.
Nearly a decade later, another gunman walked into a primary school in Dublane, Scotland, and killed 16 small children and their teacher. The gunman had been granted permits for all four guns used in the shooting, including two semiautomatic pistols.
Afterward, the British government took action to limit gun ownership by civilians. By the end of 1997, Parliament had outlawed the private ownership of nearly all handguns.
In Germany, gun buyers under 25 must certify they are psychologically fit.
In 2002, a 19-year-old expelled student returned to his high school in Erfurt, in eastern Germany, armed, and killed 16 people.
That year, the German government tightened gun laws, including raising the legal age for carrying sports weapons to 21 from 18 and requiring gun buyers under 25 to present certification that they are medically and psychologically fit.
Germany strengthened gun laws even further after another shooting in 2009, when a 17-year-old got his hands on one of his father’s guns and went on a rampage at his school in Winnenden, in southwest Germany, killing 15 people. The new regulations included allowing for random checks on weapons owners.
As of 2015, gun-related crimes were far more unusual in Germany than in the United States.
Canada goes back and forth on a registry for rifles and other long guns
Canada has had tough restrictions on handguns and automatic weapons since the 1930s. But the rules were expanded to include rifles and shotguns after a gunman with a semiautomatic hunting rifle stormed an engineering school in Montreal in 1989.
Shouting “I hate feminists,” he separated the women from the men and killed 14 female students before turning the gun on himself.
After that shooting, rifles and other long guns had to be registered like handguns and a majority of semiautomatic weapons. Gun owners were also required to obtain a license.
But the long gun registry was unpopular in rural and northern areas, and, over the objections of police forces and some provinces, was abolished in 2012.
Efforts to keep track of rifle and shotgun sales — the majority of firearms in Canada — continue to be much debated. The province of Quebec introduced its own long gun registry last year.