Assistant Chief Constable Drew Harris, head of the Police Service of Northern Ireland's (PSNI) Crime Operations, has told the press that it's 'difficult to see an end' to the threat of dissident republican violence.

Interviewed as part of documentary "The New Dissidents" Harris said it would be unwise to overestimate the present threat, but dissidents are not to be taken lightly.

'It's serious,' he said. 'It still causes the odd sleepless night. It's very difficult to see an end of this.'

According to the BBC what keeps Harris and MI5 awake is the threat from the group known as the 'New' IRA. The group was reportedly formed last year and is made up of the Real IRA, Republican Action Against Drugs (RAAD) and unaffiliated, hardened former Provisional IRA members from County Armagh and East Tyrone.

'If that starts as a trend, people may feel it's better to be within this bigger grouping,' he added. 'Hitherto they have been very diverse and mistrusting of each other.'

Harris' other concern is that a new generation of young people is being radicalized by the failure of the peace process and the wider economy to offer meaningful changes to their lives.

'Young men, even in their very early 20s, are being charged with serious terrorist offences who must have only been very small children at the time of the Good Friday Agreement,' said Harris. 'They don't have any buy-in to the peace process and almost a nihilist response in terms of what a united Ireland would be like. That's worrying.'

In the documentary the North's Deputy First Minister Martin McGuinness makes clear what he thinks of the dissidents' lack of a coherent goal, strategy or analysis.

McGuinness has called the dissidents 'traitors to Ireland,' the most damning insult that he could offer to groups that include some of his former comrades in arms. At last month's Sinn Fein party conference he pointedly asked: 'Where were they when there was a war?'

In the documentary Sinn Fein's Gerry Kelly makes opposition to the dissidents clear in a more measured way.

'I think they are wrong,' he said. 'I don't think they have an analysis. I don't think they have a strategy. But you have to deal with fact, that there are some young people in it. They get caught up in the ideology. I can understand where they are coming from.

'What I'm more critical of are the ones who - some of them my former comrades - are almost trying to plot a revolution after it has taken place.'

Asked if he had spoken to the dissidents and asked them why they were continuing the armed struggle when the war was over he was emphatic

'The answer is yes,' Kelly said. 'At this moment, the offer is out from myself, and from Gerry Adams and Martin McGuinness, to speak to them about their analysis, our analysis, and where we believe they are going wrong.

'I don't think they have an analysis. I don't think they have a strategy,' Kelly concluded.

According to the new documentary the problem with the dissidents is that they appear to have no coherent political program. At it's root all it offers is 'Brits Out' and self determination for the Irish people.

But leading dissident Derry republican Gary Donnelly says the New IRA are operating in a longer timeframe.

'The Provisional movement didn't appear overnight,' he said. 'It would probably take them (the 'New' IRA) a lot of effort and a lot of time to get up to full steam. But the reality is that as long as there's a British presence in Ireland, there will always be a respectable minority who will challenge it and who will use force of arms.'

However Harris sees no danger of a return to the dark old days of the past. 'There's not actually the broad base of support to mount a sustained campaign,' he said.

Sinn Fein's Gerry Kelly agrees. 'It is not gaining momentum because the people do not want it,' he added. 'It's as straightforward as that.'