Just nine months after a lone gunman in Christchurch, New Zealand walked into one mosque and then another and opened fire, murdering 51 people, a countrywide ban on semiautomatic weapons took effect this weekend.

The new law was first passed in April, less than a month after the shooting. In the weeks and months since then, New Zealanders have voluntarily handed over tens of thousands of their semiautomatic weapons.

It was a swift legislative and cultural change.

By comparison, in the United States, it’s been 12 years since a gunman opened fire at Virginia Tech, killing 31 people. It’s been seven years since the shooting at Sandy Hook Elementary School, where a young man killed 26 people, 20 of them children ages 6 and 7. It’s been three years since the Orlando nightclub shooting, during which a gunman killed 49 people. It’s been two years since a shooting in Las Vegas killed 58. It was two years ago that a shooter killed 17 people at Stoneman Douglas High School in Parkland, Florida. And it was four months ago that a gunman killed 22 people at a Walmart in El Paso, Texas.

In all those years, and despite all those shootings and many others in between, the US government has not passed a single piece of legislation regulating gun ownership. In fact, it’s been a full 25 years since the last time the US Congress passed a gun control law.

That was in 1994, and it was called the Federal Assault Weapons Ban. Written into the law was a provision that it would expire after 10 years. But for that decade, the law essentially banned the manufacture, sale, and possession of some military-style assault weapons, including the now popular AR-15.

A recent study found that the ban reduced the number of mass shootings during the decade it existed. And after it expired in 2004, there were several attempts to bring it back. US president Barack Obama tried to renew the ban in 2013 just months after Sandy Hook. But the Senate stood in the way, voting not to renew.

The US House of Representatives, now controlled by Democrats, passed a comprehensive gun control bill earlier this year. But so far the Republican-controlled Senate has not brought it to a vote.