As a BBC survey finds three-quarters of Britons think drugs are a problem in their area, social affairs correspondent Richard Bilton visits a typical city to gauge the impact on its communities.
A dealer is secretly filmed handing over drugs to a customer
I drove into Preston past the banks of back-to-back housing.
I saw big estates with kids running around, playing out on an early summer evening. A few areas run-down, most okay. Nothing remarkable.
And statistically Preston isn't unusual. Its drug crime is no worse or better than most other big communities.
But you cannot see drug crime by just driving around. You need a guide. Someone who sees the dealing and the using.
Someone who looks at side streets and alleyways, phone boxes and parks as places to trade.
The other side
Sarah is 34, but she looks 10 years older. She's been on heroin since she was 20, somehow bringing up four children through the chaos of her addiction.
She knows the other Preston and she's happy to show you.
"Up there, the houses at the back. That phone box."
We're driving along and she's pointing out of the window, picking out the places you can buy heroin if you want it.
We're on a big estate now. She says: "I won't name anyone, but there's a dealer on every street down here."
I point out that we're near a road where police recently raided a series of houses.
"Oh, they work hard, the police. They're good at getting dealers. The dealing doesn't happen on the street anymore. But take one dealer away and another one appears," she says.
I came to Preston because this is a place with a good reputation for tackling drug crime.
Operation Nimrod is its rather grand name. It's actually about using intelligence and the latest surveillance techniques to catch drug criminals and lock them up.
The figures are impressive - 600 arrests, more than 500 convictions, 1,200 years of sentences handed down.
Forces from across the country have come here to see what they do. And I came too.
Police in Preston have a good reputation for tackling drugs
I went to an estate where last week a series of properties had been raided.
The raids are much as you would imagine - doors smashed in, officers in riot gear, people taken away.
What comes a week later is the "reassurance police". They are there to let people know that the work behind the raids is ongoing and that dealing won't be tolerated.
"It works," says Martin O'Neill, who's lived here for two years.
It was bad when he arrived, he says, but better now. "Drugs used to run this estate but things have improved."
But not everyone feels like Mr O'Neill.
Scared to go out
A BBC poll shows that nationally many people feel drug crime is a problem where they live.
Three quarters of those asked thought drugs and drug-dealing were a problem in their area and a third of those thought drugs were causing a big problem where they lived.
I found the same view, the same concerns time and time again here.
A silent group of people who live in the shadow of drugs. People who worry about their area but are too frightened to be identified.
People like Mary. She's lived in her flat for 30 years. It overlooks where last week's raids took place.
"It is better", she told me, "but I'm still frightened. Too scared to go out at night, too scared to go down certain streets. The police do well, but drugs will never disappear. Not from here or any place."
It is a hard one for the police.
In Preston I met team after team of officers committed to tackling drugs crime.
They would not accept the view that nothing changes.
They'd point to crime figures falling, research that shows satisfaction levels rising.
But they know there is a disconnection.
You can see it in our poll, you can feel it on the streets.
There are large numbers of people across the country who are intimidated by drug crime - and tired of seeing it on their doorsteps.