In the week since Billy Wright's murder more attention has been paid to the circumstances of his death than to the reasons behind it.
To kill the leader of so volatile a group as the Loyalist Volunteer Force was an act of breathtaking provocation: Wright's erstwhile colleagues in the Ulster Volunteer Force would have been prime suspects if it had happened elsewhere.
For members of the Irish National Liberation Army to have shot him, in prison, at 10 a.m. with the certainty that they would be quickly caught and clearly identified, was scarcely credible.
But it was a deliberate action which is certain to have taken months of preparation. Wright's movements had to be watched and noted, the guns used to kill him smuggled into the Maze. Access to the roof had to be secured. Nothing had been left to chance.
Why did the INLA do it? And what did it expect to happen as a result? The questions must worry policemen and politicians alike, as friends mourn Wright and those killed in retaliation for his death; as security forces, North and South, prepare for trouble.
Even if the motive had been nothing more than revenge for the vicious activities of the LVF, no one could have expected it to pass without reprisal.
But the INLA, like the LVF opposed to the current ceasefires, has a history which points to motives more complicated than revenge.
It's often described as an ultra-left group, but that has more to do with rhetoric than reality: the names of Connolly and Tone are invoked; the affinity stops there.
Outside the areas in Belfast and south Derry where it commands support, most think of the INLA as a wing of the Provos; if anything, more extreme, less predictable and more dangerous than the rest.
Two of its members, Dominic McGlinchey and Dessie O'Hare, achieved notoriety in the Republic in the 1980s; in the North, the public became more familiar with reports of deadly faction fighting.
The INLA has been responsible for the deaths of about 130 people in some of the most callous actions of the last 22 years. Indeed there have been occasions when it seems to have chosen those targets most likely to provoke a violent or repressive response.
It was INLA members who opened fire on a Pentecostal prayer meeting in a church hall at Darkley, south Armagh, in November 1983. Three elders died in the attack.
It was the INLA which set the bomb that killed Margaret Thatcher's friend and spokesman on Northern Ireland, Airey Neave.
And it was an INLA group which went into the Shankill Road in June 1994 to kill three loyalists within earshot of a paramilitary conference. If it was retaliation they wanted, they succeeded with a vengeance.
But, as in all such incidents, those who suffered the vengeance were not the gunmen who provoked it. In this case, it was a crowd who'd gathered in a country pub to watch a soccer match on television when loyalist terror struck.
Six of the pub's customers died that night. And the name, Loughinisland, was added to Darkley and Greysteel in the list of places known only to the outside world for the shame of sectarianism.
Not that the INLA ever acknowledged sectarian motives. Some of its members preferred the comparison with two terrorist organisations which gained notoriety in mainland Europe between the end of the 1960s and the early 1980s.
One was the Red Army Factions led by Andreas Baader and Ulrike Meinhof in Germany; the other, Italy's Red Brigades, kidnapped and murdered the Christian Democrat leader and former Prime Minister, Aldo Moro.
Both, like the INLA, claimed to be of the left; and the left dismissed their claims. Both believed the state could be provoked to react in a way that would win popular support for their cause; and both failed. The INLA's origins were in a split in the Official Republican movement following that organisation's decision to concentrate on politics in 1972, more than two years after the departure of the Provisionals.
Ironically, it was Seamus Costello, the first Sinn Fein leader to play a part in constitutional politics, who led this second breakaway, partly because he believed the Officials were not aggressive enough.
Costello was a clever, forceful but erratic politician. As a member of Sinn Fein he had won, and taken, seats on Bray Urban District Council and Wicklow County Council in the 1960s; and he argued persuasively that others elsewhere in the State should follow suit.
But when he set up the Irish Republican Socialist Party at the end of 1974 it was taken for granted that, with the usual disclaimers of any connection between the two, the party would have a military wing.
With its latest strike, the INLA has succeeded in provoking a response, but not the response which Costello and his followers once expected. It has not united the workingclass people of Northern Ireland, never mind the people of North and South.
What it and its loyalist counterparts have done is to undermine the hopes of progress which had survived the months of inter-party manoeuvring in Belfast.
Where it had been expected that a lead given by the parties of the centre - the SDLP, UUP, Alliance - would create a movement which others might be encouraged to join, Mo Mowlam must struggle to keep talks alive.
Far from being led by those at the centre, the movement is controlled by forces outside the discussions and opposed to the ceasefires, making it more difficult for the parties at the centre to speak of compromise.
It's not that people will move ground to support the INLA on one side and the LVF on the other; rather that at moments when these organisations inspire fear, and the risk of involvement by mainstream paramilitaries on either side continues to grow, polar attitudes of them and us will dominate.
This is not the time for people in the South to add to the polarisation as they tend to do whenever tempers flare. It's time, rather, to remember the warnings given by Archbishop Robin Eames, David Ervine and others about the feeling among loyalists that things are going against them.
It's a feeling the Government and the media in the South can help to reduce and in time remove. It won't be done by thinking and talking of unionists as people who'd been led astray.
We should also stop behaving as if anyone who criticised the nationalist position in the South was talking out of turn, less entitled to be heard than those who take an interest in Ireland from a distance of 3,000 miles.