When Queen Elizabeth is in the business of shaking hands with Martin McGuinness, neither of the two governments favours delving back into the past any more than they have to
HE Smithwick inquiry's findings will not generate shock in Northern Ireland, where unionists for years complained that IRA sympathisers were active in various parts of the Republic, particularly in the Dundalk area.
Such complaints long pre-date the 1989 Breen and Buchanan killings, going back to the earliest days of the Troubles. The Smithwick findings will thus be viewed by many unionists as confirmation of a belief firmly held for decades.
It is however unlikely to have a serious impact on Anglo-Irish matters, since London and Dublin both regard relations between them as little short of a golden age. Both are anxious to preserve that.
There have been many instances of London-Dublin disagreements over the actions and alleged actions of the British security forces in connection with incidents such as Bloody Sunday and the Dublin-Monaghan bombings.
While these have been sources of metropolitan disagreement for years, the two governments are at one in agreeing that these and other issues should not be allowed to disrupt their relations, or to undermine the peace process.
The Cameron administration is thus unlikely to brandish the Smithwick report to condemn Dublin for the performance of previous Irish governments. In the modern era, when Queen Elizabeth is in the business of shaking hands with Martin McGuinness, neither of the two governments favours delving back into the past any more than they have to.
The queen expressed the new tone when she said that "we can all see things which we would wish had been done differently or not at all."
But a number of unionist representatives will argue that their traditional distrust of the south has just been vindicated.
Years ago, when DUP MP Jeffrey Donaldson named a garda officer stationed in Dundalk as having republican sympathies, it was the latest in a series of unionist allegations centring on the station. Part of the argument was that one of the reasons why the IRA in south Armagh was so dangerous was because gardai and the Irish army were reluctant to move against it robustly.
On the wider level, some unionists still hark back as far as the Haughey era, alleging that some southern politicians connived in the early days of the Provisional IRA.
The unionist charge sheet includes complaints that extradition of republicans was too difficult, prison sentences in the south were too short, and that not enough action was taken against IRA arms dumps and training camps. It was also said that the presence of Articles 2 and 3 in the Irish constitution, now removed, provided encouragement to the IRA.
Thus when DUP minister Arlene Foster last night criticised the southern authorities, she was continuing a long tradition of condemnation.
Mrs Foster, who has in recent months led delegations to meet Dublin ministers to speak of such matters, added: "This report focused on one incident which resulted in the murder of two police officers. There are many other outstanding issues which have still not even been acknowledged never mind properly investigated by the Republic of Ireland."
Sinn Fein, meanwhile, will not be expected to shed any light on such issues. Although republicans will have intimate knowledge of many of these matters, they do not offer information on them.
It is clear that there will be more unionist delegations to Dublin seeking to discuss not just Dundalk but all such issues, some dating back almost half a century.