Disaffected young people are playing a key role in the increase in violence by dissident Republicans that resulted in PC Ronan Kerr's death, the Northern Ireland Secretary warned last night.
Owen Paterson conceded that the "old Provisionals" opposed to the peace process had managed to exploit unemployment and poverty to recruit teenage followers too young to remember the Troubles.
He said the Government must try to do more to tackle problems on "estates where there are sadly disaffected unemployed young people".
Mr Paterson acknowledged that dissident activity was growing and pointed to a sharp rise in the numbers of people arrested on suspicion of terrorism in Northern Ireland from 106 in 2009 to 210 last year. The rate has continued to increase this year, he added, with 49 arrests so far in 2011.
Mr Paterson said the security services were on alert for attempts by dissidents to strike again during campaigning for next month's elections to the Northern Ireland Assembly. He said the violent dissidents were a "small number of young people" but that police and security services were not underestimating their potential danger.
An unemployed 17-year-old youth is on remand for the murder of Stephen Carroll, the previous Northern Ireland police officer to be killed.
The radicalisation of teenagers could not be countered just by policing and had also to be tackled economically, added Mr Paterson.
Citing moves to cut corporation tax in the province, he said it was a crucial part of the Government's strategy to boost the province's economy to the extent that even its most deprived areas benefited.
"With this political stability, we have a wonderful opportunity to really crack on and galvanise the economy.
"My hope then is the rising tide of prosperity is completely colour-blind, it will wash into every one of those estates where there are sadly disaffected unemployed young people and they will all be lifted by it.
"We all have to be vigilant – [the terrorists] are really beyond any rational persuasion as far as anyone can see. Saturday's vile murder will, in my view, achieve absolutely nothing. If they do try to disrupt the elections, they again will not achieve anything."
He said of the dissident groups: "They are very small in number compared to the 1.8m population [of Northern Ireland]. They are wholly unrepresentative, they don't have a single elected representative, but we don't underestimate them, their danger."
Constable Kerr had been "exactly the sort of person we would like to see building a new Northern Ireland within the police force", Mr Paterson said.
He insisted that the murder of PC Kerr had only succeeded in uniting disparate communities across the province in horror and disgust.
He said: "There is cold, utter determination that these very, very small number of people, who are completely unrepresentative of modern Northern Ireland, won't divert any of us."
Mr Paterson added that there had been "huge success" in boosting the proportion of Roman Catholics in the police service from eight per cent in the final days of Royal Ulster Constabulary to almost 30 per cent today.