MI5 estimates around 2,000 Muslims in the UK pose a potential terrorist threat
The government's plan to tackle violent extremism will require decades to take effect, a top police officer has said.
The Prevent strategy, forged after the 2005 London bombings, aims to work with communities to avert terrorism.
But West Yorkshire Chief Constable Sir Norman Bettison told the BBC Two's Generation Jihad programme it would take "probably 20 years" to bear fruit.
He added the UK's whole community including Muslims "could do more" to fight against extremism.
The failed attack on the plane above Detroit on Christmas Day brought the threat from radicalised young Muslims closer to home.
The bomber, Umar Abdulmuttalab, was in touch with radical preachers and activists when he was a student in London.
'CONTEST' COUNTER-TERRORISM STRATEGY
Pursue: Stop terrorist attacks
Prevent: Stop people from becoming terrorists or supporting violent extremism
Protect: Strengthen UK's protection against terror attacks
Prepare: Improve resilience and reduce impact of attacks which cannot be stopped
MI5 estimates there are about 2,000 Muslims living in the UK who pose a potential terrorist threat - plus an unknown number who sympathise with extremist ideology.
Prevent is one of the major planks of the government's counter-terrorism strategy, known as Contest, designed to combat al-Qaeda-inspired violence and radicalisation.
About £140m is being spent annually on Prevent programmes, many of them administered by local authorities. Some more sensitive projects come under direct Whitehall control.
Sir Norman, who is the Association of Chief Police Officers' representative for policy on tackling violent extremism, said the problem would not be solved quickly.
"I think it's a generation of treatment to prevent the infection spreading and I think that will take us probably 20 years," he said.
Three of the 7/7 London bombers came from his West Yorkshire base and the constabulary also covered the home of Hamaad Munshi, Britain's youngest convicted terrorist.
Sir Norman said that while he was aware that there was a fine line between winning the confidence of the Muslim community and alienating it, there was also a need for the community to help the police.
"I'm looking for the community to work much more closely with the police in identifying young people that they have concerns about in terms of the people that they're mixing with, the sort of websites that they're going on to and the material that they're reading," he said.
"Now, that information can only come from the community itself."
Sir Norman continued: "I think we have to be alert and conscious of the risk that's ever-present and prepared to interdict and prepared to share information.
"So the community as a whole could do more and the Muslim community is a part of that."
The first part of Peter Taylor's investigation Generation Jihad will be shown at 2100 GMT on 8 February on BBC Two.