The organisers of today's event have every right to come to Dublin to express their grief and anger at being bereaved by the IRA. But they must face some unpalatable truths, writes Susan McKay.
As soon as he heard that the Rev Ian Paisley had stood up in the House of Commons and said Eugene Reavey was responsible for the Kingsmills massacre, Alan Black went straight to the Reaveys' house in Whitecross, south Armagh. He told Reavey that he knew he was innocent.
This was in 1999. Black was the sole survivor of the sectarian massacre, which saw up to a dozen IRA gunmen ambush a bus carrying workmen home in January 1976. They lined the men up and raked them with automatic gunfire. Ten men died. Black was hit 18 times.
Families Acting for Innocent Relatives (Fair) is to hold a rally in Dublin today to draw attention to the suffering of the victims of terrorism. However, this is an organisation which has effectively branded an innocent Catholic man the mass murderer of his Protestant neighbours, causing him intense anguish and, inevitably, putting his life at risk.
The PSNI has stated that it had no reason to suspect Reavey of any crime, let alone of masterminding one of the worst atrocities of the Troubles. But Fair defiantly continues to carry the allegation through a link to Paisley's speech on its website, despite repeated demands by the police for it to be removed.
Reavey witnessed the immediate aftermath of the massacre, which took place near his home. He was driving to Newry and happened upon it. He and his family were on their way to Daisy Hill hospital to collect the bodies of two of his brothers, John (24) and Brian (22).
They had been shot dead the previous night when loyalist gunmen burst into the family home. Three members of another local Catholic family were also murdered that night.
Reavey was also going to visit his younger brother, Anthony, who had been badly injured in the attack. The bodies of the murdered workmen were being brought into the mortuary when he arrived. He went into the room where the shattered families were gathering, and wept with them. Alan Black and Anthony Reavey shared a hospital room. Black lived. Reavey died.
Black has said that earlier on the day they met their deaths, the men on the bus had spoken with horror about the murders of the young Reaveys. He has remained a close friend of the Reavey family since the events of those terrible days.
Paisley's Westminster claim, that Reavey was a "well-known Republican" who had "set up" the massacre, was made under parliamentary privilege.
He spoke of the "wild men" of the IRA who were free because the British government had not been ruthless enough in putting down terrorism. He said his information came from police files.
The deputy first minister, the SDLP's Séamus Mallon, expressed outrage. Reavey went to the chief constable of the RUC, Ronnie Flanagan. Flanagan said he had "absolutely no evidence whatsoever" to connect him with the massacre, and that no police file contained any such allegation.
Paisley has not retracted it, and on the 30th anniversary of the massacre this January, Willie Frazer, Fair's leading spokesman, and DUP MP Jeffrey Donaldson claimed once again to know the perpetrators.
The Reavey murders were carried out by a gang which included men who were dual members of the illegal UVF and the British security forces. This gang was responsible for multiple sectarian murders, including the 1974 Dublin and Monaghan bombs, which killed 33 people.
Evidence including the testimony of a former member of the gang suggests that Robert McConnell, a UDR soldier, was a member. Before he died, Anthony Reavey described one of the gunmen who shot him. It was an accurate description of McConnell.
He was murdered by the IRA later in 1976. When Fair was set up in 1998, to remember what "Irish republican death squads" had done to south Armagh Protestants, "without justification or reprisal", his nephew, Brian, became a prominent member.
Willie Frazer is open about his belief that the loyalist paramilitaries were a necessary part of the war against the IRA. During a protest against the release of republican prisoners as part of the Good Friday agreement, he was asked about loyalist prisoners. "They should never have been locked up in the first place," he replied.
He told me once that, while he didn't condone the murder of "innocent Catholics", he had "a lot of time for Billy Wright", who "called a spade a spade". The notorious loyalist broke away from the UVF to form the Loyalist Volunteer Force in 1996 to kill Catholics in support of the Orange Order's right to march through the Catholic part of Portadown.
Another Drumcree supporter said of Wright, "He may be a psychopath, but he's our psychopath". Since 1996 at least 12 people, including three children, have been murdered in parades-related violence.
Frazer, who is an Orangeman and an Apprentice Boy, said he understood why soldiers and police passed information about republicans to loyalists. He applied for a weapon for his personal protection and was turned down in 2003 because, according to police, of "reliable intelligence" that he "associated with loyalist terrorist organisations". He denied it and sought a judicial review - it was refused in 2004.
The Orange Order welcomed the UDA leader, Johnny "Mad Dog" Adair to the Portadown protest in 2000.
Last summer, after the Parades Commission put restrictions on the Order's Whiterock Road parade, Paisley declared: "This could be the spark that kindles a fire there will be no putting out." The UVF offered to force the march along the order's preferred route (past Catholic homes).
The order called the people out to support it. Days and nights of violence followed. Orangemen lunged with pikes and ceremonial swords at policemen. There were shouts of: "Are youse Fenians in disguise?"
Today's event is billed as a Love Ulster rally. This campaign was launched last July with the symbolic landing at Larne harbour of bales of newspapers, bearing the title "Love Ulster". This recalled 1914 when the UVF ran guns to Larne to arm unionists against Home Rule. At least one loyalist paramilitary leader was among those unloading the papers, smiling cheerfully for the invited cameras.
The July publication is full of harrowing accounts by victims and survivors of IRA atrocities, including Bloody Friday, La Mon, Kingsmills, Enniskillen and Shankill.
There are photographs of carnage. Alan McBride, whose wife died in the Shankill bomb in 1993, said of the paper: "Blood was pouring from it".
However, it saddened him that there was no acknowledgment that the unionist community had "caused pain and grief as well".
Catholics feature in "Love Ulster" as IRA killers. Paisley declared at an Independent Orange Order gathering in 1997 that "the entire pan-nationalist front is united behind the beast of fascism, the IRA".
Love Ulster warns that Ulster is at "crisis point" and on the verge of being "sold out" into a United Ireland. It calls on Protestants to unite. This call for ethnic solidarity and militancy is the core of DUP politics. It was also a founding principle of the Orange Order.
Soon after its formation at the end of the 18th century, an Armagh squire wrote of his reliance on the local "Bleary Boys". These were "stout Protestants of a character somewhat lawless", but loyal.
Fair and the DUP insist the war is not over and that the enemy can still be defeated. A previous effort led by Drumcree stalwarts to rally Protestants around a new Ulster covenant was launched in Ballymena in 2001 with calls from one speaker for "B52 bombers over Dublin".
Willie Frazer is a hurt man. The IRA murdered his father and four of his relations. Michelle Williamson, whose parents were killed in the Shankill bomb, expressed the intensity of this pain when she said of the surviving bomber, Seán Kelly: "You are like a disease in my bones, and the only cure is justice. To say I hate you doesn't begin to describe how I feel."
Robert McConnell may have murdered the Reaveys but to his family he was the man who looked after his sick brother and disabled sister.
The families bereaved by the IRA have every right to their grief and their anger, and every right to come to Dublin to express it. The news that the bands which will accompany today's parade will not play as they pass the sites of the Dublin bombs is welcome.
Fair, Frazer admitted to a House of Commons select committee hearing last year, is controversial. "We are seen as the bad boys within the victims sector," he said.
This is largely because of its aggressive insistence that there are "innocent" and "genuine" and "real" victims, and there are others who have no right to call themselves victims at all.
According to Fair and the DUP, Eugene Reavey is in the latter category. It is an appalling lie.