Despite all of the speculation over the years, only the IRA knows the true extent of its arsenal.
Weaponry: Decommissioned, says arms body
However, General John de Chastelain, head of the international body charged with decommissioning paramilitary arms in Northern Ireland, says that the IRA has now put its weapons beyond use.
While Gen de Chastelain says he will not reveal the exact nature of what he has seen rendered either unusable or unobtainable, in his briefing he gave some details of the decommissioning process - and suggested strongly that assessments published by Jane's Intelligence Review, themselves drawn from security estimates, were accurate.
The IRA's actions in Northern Ireland long ago left the security forces in no doubt that the organisation was in a position to fight a long campaign, providing it had the will to do so.
When Northern Ireland slid into conflict in the late 1960s and the Provisional IRA emerged, it was badly armed, relying on old guns from previous campaigns, commercial explosives and a complete lack of the logistical support needed to fight a campaign.
But as it reorganised and grew, it acquired a wider range of weapons from around the world and the skills to make increasingly sophisticated home-made bombs.
ESTIMATES OF WEAPONRY
The bulk of the IRA's weaponry was Libyan supplied. It included machine guns, rifles, handguns, ammunition, Semtex plastic explosives, surface-to-air missiles and rocket launchers. However, not all of its was useful to the kind of conflict that the IRA wanted to fight, according to experts at Jane's.
Security services have estimated the IRA has held about 1,000 rifles, thought to be mostly AK-47 assault rifles, perhaps two tonnes of Semtex, and large quantities of ammunition for the various firearms. The IRA was also known to hold a handful of highly accurate Barrett Light 50 sniper rifles, a weapon used to kill British soldiers in the border area of south Armagh.
2 tonnes of Semtex
20-30 heavy machine guns
7 Surface-to-air missiles (unused)
7 flame throwers
11 rocket-propelled grenade launchers
90 hand guns
Source: Security estimates/Jane's Intelligence Review
In terms of heavy weaponry, the IRA is thought to have held Russian-made machine guns used to target helicopters in ambushes, successfully bringing one down in 1988. The IRA's store of surface-to-air missiles, acquired for the same purpose, were never used. In both cases, analysts believe the IRA may have decided they were not appropriate weapons for their aims.
Semtex was however the most significant of the weapons: the virtually odourless plastic explosive is relatively easy to use because it is stable, unlike home-made bombs.
It however became a key component in the home-made bombs and mines, typically forming a small part of a larger device with sophisticated timers and detonators.
Another key device is the home-made mortar. This is basically a modified tube that can be aligned to fire an explosive round at a target, typically inside a security forces installation from some distance away.
The IRA's largest mortar was first used in 1992 and pointed towards sophisticated ballistics and engineering skills within the organisation.
WHAT THE COMMISSION SAID
General John de Chastelain said the decommissioning took place over a number of long days that began at 6am and ended late at night.
We don't know where the decommissioning happened, other than somewhere on the island or Ireland.
He and his two other independent inspectors say they handled every gun and rifle, weighed every box of ammunition and catalogued every piece of weaponry during the decommissioning.
Semtex: Key weapon
He said that the amounts that they had handled and witnessed being "put beyond use" were consistent with the range of estimates that the security services had provided to them first in 1998 and then updated in 2004.
The total amount of weaponry was "greatly more" than that dealt with in the previous IRA decommissioning moves. Andrew Sens, another member of the commission, said he had handled "an immense amount of material".
Gen de Chastelain said that it would probably take the IRA "a hell of a long time" to amass the same weaponry again, should it want to: this is a major concern for many sceptical of the IRA's intentions. Many unionists believe that the IRA retains the capacity to re-arm, not least because of its alleged involvement in the £26.5m Northern Bank robbery in 2004.
However, the general said that he had received "second-hand" intelligence to suggest that IRA members had been "scouring" the country to gather in weaponry from members in the weeks running up to his formal meeting with the IRA for the decommissioning.
Gen de Chastelain said there had been "a lot of ammunition". Some of it was still sealed in the manufacturer's box, indicating it had been in storage for many years. Some of it came in "loose", or in ammunition belts, indicating it had been recovered from individuals, local dumps or "active service units", he said.
Gen de Chastelain said he had seen rifles, particularly AK-47s, machine guns, ground-to-air missiles, explosives, explosive material, mortars, flame throwers, hand guns, timer units and ballistic caps, a device that improves the flight path of a missile.
While the majority of the arms were heavy weaponry, the team had also decommissioned improvised weaponry.
Some of the weaponry was "very old", said the general. He had handled a Bren machine gun, a 1930s weapon that he had trained with at the start of his military career.
He said that it was likely that given the age of some of the weaponry, and the condition in which it was presented to his team, it was entirely possible that the IRA itself no longer knew exactly what arms it had been keeping.
Arms dumps may have been forgotten about, particularly if someone charged with managing it had died.