There may be a simple answer to the Semtex mystery — a way of explaining how that explosive came to be used by republican dissidents in an attack on the police in Lisnaskea a week or so ago.

The answer could be in something that was said by the IRA in 1999 — long before the decommissioning process began, and long before that recent failed attempt to kill PSNI officers in Fermanagh.

There is a ‘P O’Neill’ briefing now almost ten years old.

Its opening sentences read: “Following thorough investigations over a prolonged period, the IRA has established that a small amount of its weaponry has been stolen by some individuals who resigned from the IRA over a year ago.

“The weapons involved were secretly misappropriated by those individuals prior to their defection.”

Those defections are at the roots of the dissident campaign —and those who left the IRA included significant figures in its “quartermaster” and “engineering” departments.

Their business was weaponry —developing it as well as storing arms that had been smuggled into Ireland from Libya and elsewhere.

The ‘P O’Neill’ briefing of Wednesday, February 3, 1999 continued: “We have recovered some but not all of the stolen weapons.

“The IRA will continue its investigations until all its weaponry has been recovered.”

We would be in a very different place if each one of those attacks had come off

In that briefing there could well be the answer to all those recent questions — a possible explanation for how weaponry once under the control of the mainstream IRA found its way into the hands of the dissidents.

Those who knew where it was hidden stole it.

There is no suggestion that the IRA or elements of it are assisting the dissidents — those republicans opposed to the peace process and still trying to force change through an armed campaign.

In the latest phase of attacks their aim is to kill a police officer, and they have come close to doing so.

“They are trying all right,” commented the retiring assistant chief constable Peter Sheridan.

“We would be in a very different place if each one of those attacks had come off.”

The big question is how to stop the dissidents, and Peter Sheridan believes politicians can help.

“The devolution of policing and justice would put another nail in their coffin,” he commented.

There are significant voices who would agree with Sheridan.

But remember the dissidents came back after Omagh — after being forced into hiding and shamed into the shadows in the wake of the horror of that bombing ten years ago.

They have not the political or military wherewithal to recreate the “war” of the IRA or to destroy the peace process.

But they could kill a police officer — and if they achieve that aim, particularly through the use of old IRA weaponry, then that will raise more questions on top of the many already asked after that Semtex incident in Lisnaskea.

In this newspaper some weeks ago Brendan Duddy, the man who for decades was a secret link between the British Government and the republican leadership, made an argument for talking to the dissidents.

“What we are doing is opening a door that might just save some human being,” he said.

He also had this question for what he described as “alternative” republicans.

“Will shooting a serving police officer help in any way whatsoever to advance their cause?”

That was back in April, and those dissidents are still trying to be heard through their violence.

The events of recent days — including that use of Semtex in Lisnaskea — do not raise serious questions about the decommissioning process. There is a possible explanation for that.

The big question is how best to silence the guns and the bombs of those still trying to force change through an armed campaign.