The IRA was passive and dormant during the late 1960s – so much so that graffiti proclaiming “IRA – I ran away” appeared on walls in west Belfast when the riots and burnings began.  At the start of the Troubles, it had no political wing to speak of.  By the time they ended, that wing, Sinn Fein, had become the strongest Nationalist party in Northern Ireland.  With the ballot box in one hand and the armalite in another, it had won the backing of a big slice of the province’s Catholic voters.

Comparisons between Irish Republicanism and Islamist extremism can be flawed.  For example, the former was not international in scope (though it was backed during the Cold War by the Soviet Union), while the latter is.  Young men from the Falls Road or the Bogside didn’t travel abroad to learn how to murder before returning to the province as fully-fledged terrorists – not in large numbers, anyway.  There was no Republican equivalent of Saudi Arabia, pumping out some Gaelic version of Wahabiism.  The IRA was at least as Marxist as it was Catholic.  Islamism has a sweep and religiosity that Republicanism lacks.

None the less, the parallel isn’t entirely misplaced, and in one important way it is apt.  Attitudes to the IRA among the province’s Catholics ran in a spectrum from outspoken hostility (think of those who served in the police and security forces) all the way to outright support.  But the crucial section of voters were those in between, who didn’t support Republican means but sympathised with its end – namely, a United Ireland.  When a grisly terrorist atrocity took place, such as the Enniskillen bombing, sympathy swung away from the IRA and Sinn Fein.  When its horror began to fade, money and votes crept stealthily back.

Some claim that the higher Sinn Fein’s vote rose, the more the IRA backed off violence – thereby setting the scene for the Belfast Agreement.  Others say that the terms of that Agreement, and Ulster’s settlement, were far too favourable to the IRA – that it forced the State to a deal on its terms.  But whatever view one takes, it is very hard to argue that there was ever a solution to Northern Ireland’s problems that consisted of security alone.  Security and politics went hand in hand.  And that meant trying both to win Nationalist support from the IRA, and to use Nationalist opinion to force it to a ceasefire.

Today, approximately one in 800 young Sunni British Muslims are fighting for ISIS in Syria and Iraq.  This is a tiny percentage, just as the number of Nationalists signed up to the IRA during the late 1960s was a tiny percentage.  But it would be even smaller – and some of those young men would not have been able to make their way abroad at all – were there not a swamp of sympathy, to borrow Michael Gove’s phrase, in which they can swim.  Again, this is a rough affinity not for ISIS’s means, but its ends: that’s to say, for a political dispensation in which people are treated on the basis not of the citizenship they share but of the religion they practice.

Some – learning nothing from Britain’s experience in Northern Ireland – argue that security, not politics, can alone provide the answer to the Islamist challenge.  They favour the removal of passports from suspects, the stripping-away of citizenship, the return of control orders – even internment without trial.  Others, going to the opposite extreme, say that politics, not security, provides the solution: that such measures corrode the civil liberties, justice and human rights which make liberal democracy superior to Islamist tyranny in the first place.  At first glance, these two tendencies seem to be opposites – to have nothing in common at all.

Yet in some respects they are strangely alike.  Both favour shooting the crocodiles, to deploy Gove’s phrase again –  that’s to say, preventing terrorism and imprisoning terrorists (the first lobby lip-smackingly, the second slightly hesitantly).  Both also fight shy of draining the swamp: the security lobby because it thinks that this is a waste of time, and civil liberties enthusiasts because, in some cases, it believes that this would be institutionally racist, not to say Islamophobic.  This view is wrong.  In some ways, it is Britain’s Muslims themselves who are most at risk from the swamp’s growth.  It is their children who are most at risk from indoctrination by terrorists in Iraq or zealots in Birmingham.

With security, the levers are visible and obvious, and their use should depend on circumstances.  There is a clear case for stopping young men from travelling to Iraq and Syria to learn how to practice terror, and for preventing those who have already left from returning.  This means prosecutions, the targeted use of more passport and citizenship removals (some have already taken place), the use of the narrowed-down Prevent programme (in effect, the Channel Project) and the toughening up of TPIMs.  It should not mean the return of Labour’s discredited Control Orders, from which one in six suspects absconded.  Nor should it mean bringing back the Communications Data Bill.

In an national emergency, internment might be justified. But we are not there yet, and may well not get there at all. Even to float one risks sounding faintly hysterical.  But that is exactly the territory in which the Prime Minister now finds himself embroiled.  Yesterday, he warned that Britain faces the “greatest and deepest” terror threat in its history.  He has at once to push for new security measures while trying to keep mainstream Muslim opinion onside.  He has to get new plans for, say, hardening TPIMs past the Liberal Democrats.  He has to watch against being ambushed by Ed Miliband, as he was last summer over Syria. He has to win over his own backbenchers in the wake of the Carswell defection.

Above all, he has to convince sceptics that his policy is not driven by panic, fear, headlines, and feeding the media beast – that there is more to the package he will outline next week than a reaction to one murder, however terrible.  Draining the swamp is perhaps the hardest task of all, precisely because the levers which might help to do it are neither obvious nor visible.  There is plenty of local opposition in mosques to ISIS.  But it has little national projection.  This is in the nature of Muslim communities in Britain, which are diverse religiously, ethnically and by way of national background.  There is no Islamic equivalent of the Board of Deputies, nor could there be – not yet, at any rate.

Cameron has at least attempted to introduce some certainty and clarity to the Government’s counter-extremism policy, while simultaneously striving to win as much support for it among British Muslims as possible.  The Munich speech was made.  Zakir Naik has been excluded.  The Muslim Council of Britain has been placed in quarantine.  Gove came to the aid of Muslim parents whose children were targeted by extremists in Birmingham.  (Read John Ware’s gripping account in this month’s Standpoint.)  What is lacking is not so much theory as implementation: few of the recommendations of the Government’s own extremism taskforce have been acted upon.

Early in the Parliament, the Prime Minister considered appointing Maajid Nawaz of Quilliam (now the Liberal Democrat candidate for Hampstead and Highgate) as a special adviser in Downing Street responsible for ensuring that his counter-extremism policy was implemented.  This bracing idea never came into being.  My recommendation was and remains to appoint Lord Carlile.  But at any rate, the “poisonous ideology” to which Cameron refers cannot be tackled by security measures alone.  The lesson of Northern Ireland applies.  Countering extremism and violence needs more than testosterone.  It requires grind, application and patience. It needs brains as much as muscle.