The “excellent” work of police and other agencies in driving down knife crime in Glasgow and other Scotland cities was praised by Theresa May this week.

The prime minister told the Commons that Scotland’s public health approach to reducing knife crime will form part of the UK government’s response to the soaring number of young stabbing victims across England.

Yet it is less than 15 years since Glasgow was branded the murder capital of Europe by the World Health Organization. In 2004-05, there were “137 homicides (which include murder and culpable homicide figures) in Scotland - in Glasgow, there were 40 cases alone, double the national rate”, reports the BBC.

By 2016-17, the number of people admitted to Glasgow’s hospitals with slashes and stab wounds had fallen by 65%.

So what happened?

What did Glasgow do?

Glasgow police set up a Violence Reduction Unit (VRU) in 2005 as part of a nationwide scheme aimed at stemming the tide of knife crime. The initiative takes a “public health approach” to violence, treating it like a disease and dealing with the causes rather than the symptoms.

Police work with teachers, social and health workers to collate and share knowledge of people involved in gangs.

Officers found that “Glasgow’s roughest areas were also its poorest, with the highest rates of addiction, domestic abuse and teenage pregnancy”, says The Economist.

Dr Christine Goodall, director of Glasgow-based charity Medics Against Violence, told The Guardian: “It’s absolutely not just a policing issue, it involves everybody - schools, communities, hospital, prisons, and we work in workplaces as well.”

Goodall says that a key part of tackling the issue is to educate young people, who “carry with them a lot of myths about the safety of violence”, about the reality of knife crime and its dangers.

However, some commentators argue that this holistic approach has not been the sole main driver of the fall in knife crime.

Last year John Carnochan, co-director of the Scottish Violence Reduction Unit, a national centre of expertise in tackling violence, told reporters that while prevention was a major part of the project, criminal justice “still needed to be there and seen to be done swiftly”.

“Sometimes it gets portrayed that we didn’t do that. But we increased stop and search, we spoke to the government and they changed the legislation to increase the sentence for carrying a knife. Things were bad and we needed to demonstrate we were serious,” Carnochan said.

Would it work in England and Wales?

Those south of the border “are taking a keen interest in Glasgow’s success”, says The Economist. Knife crime in England and Wales has risen by 54% over three years, and the murder rate in London is at its highest point in decades.

Metropolitan Police Commissioner Cressida Dick, London Mayor Sadiq Khan and Labour leader Jeremy Corbyn have all gone to Carnochan for advice, but according to The Spectator, he found them to be bad listeners. “I don’t think they were happy to hear that stop and search is an integral part of stopping knife crime,” Carnochan said.

Scotland’s former chief medical officer, Sir Harry Burns, told The Economist that the greatest feat achieved in Glasgow had been giving young people a sense of purpose and hope.

That theme was picked up by a 19-year-old south London man interviewed by HuffPost as part of an investigation into what teenagers think should be done to tackle the knife crime epidemic in the English capital.

“Nowadays, there aren’t many youth clubs for people to go to. If there were more a lot of young people wouldn’t be on the streets and getting up to things they shouldn’t be,” he said.

“Do you see all of those fancy, luxury buildings that are popping up left, right and centre? The money and space spent on that can go towards building more youth clubs - more of those are needed.”

Penelope Gibbs, director of campaign group Transform Justice, is calling for the launch of a London initiative to “offer these boys a different aspiration just as the Glasgow authorities did”.

In an article in London Evening Standard last year, she wrote: “The provision of treatment for trauma, training opportunities, and jobs may seem like soft justice. But prison is a dead end. We need practical, common-sense solutions if we are to stem the flow of bodies.”