The furore over what seems to be warfare between several intelligence services in Northern Ireland draws attention to the problems which can be posed in democracies by such rivalry.
Yet, as our history demonstrates, there is a lot to be said for having at least two domestic intelligence services, for at times it can be useful for one to keep an eye on the other, as well as on sources of subversion.
This emerged early on in the history of our State. Shortly after the Civil War it became known that de Valera, who had been on the run from the Irish Free State government, intended to address a meeting in Ennis. The director of Army intelligence, a 24-year-old history professor in UCC, James Hogan, learned of a plot by "some of Michael Collins's men", who may have been associated with a separate intelligence agency in Oriel House, to assassinate him there.
When James Hogan reported this to the government, Kevin O'Higgins insisted that this attempt must be pre-empted at all costs, and Hogan got the Army to take de Valera into protective custody at the meeting - a friendly action that de Valera seems not have fully appreciated, then or later.
(With others, de Valera was released from internment a year or so later, enabling him belatedly to take up his duties as the second chancellor of the National University, of which I am now the fourth. He had been elected to this post by graduates three years earlier, shortly before the signature of the Treaty, but had not been able to attend Senate meetings. On December 7th, 1921, as chancellor, he had attended a function in honour of Dante at the Mansion House. On the way in, my father and Eamon Duggan handed him a copy of the Treaty which they had just brought from London, where it had been signed in the early hours of that morning. Their handover of this document was received in a manner chilly enough to foreshadow de Valera's hostile reaction to it when the Dáil met to consider its ratification.)
Ten years later, the director of Garda intelligence, David Neligan, helped foil a planned coup by Army generals designed to prevent de Valera acceding to power democratically after the election due in 1932. The generals sought to persuade the Garda commissioner, Eoin O'Duffy, to join in the plot. But, as I heard personally from David Neligan in 1969, he brought the same James Hogan (who was something of a theologian as well as a historian) to see O'Duffy to persuade him, after several hours of argument, to abort the project on theological grounds.
It must be said that during the second World War our two intelligence services operated most successfully together. By 1942, Garda intelligence had broken the power of the IRA, which only three years earlier had been sufficiently well organised to steal the Army's whole ammunition supply - most of which was subsequently retrieved.
Meanwhile, Army intelligence, under the legendary Col Dan Bryan, assisted with the capture of all the German agents sent here to plot with the IRA.
Under de Valera's authority, Army intelligence worked closely with British and US intelligence services to counter a German invasion and assist in other ways with the Allied war effort under the cover of a "neutrality" that successfully deceived the Germans. Some 25 years after the war, the value of having two such services was again demonstrated when Garda intelligence exposed a plot to import arms without the knowledge or authority of Taoiseach Jack Lynch.
There is, however, a danger that a multiplicity of intelligence services will trip over each other, and this seems to have happened repeatedly in Northern Ireland in the past 30 years. The burgling some years ago of the offices of the Stevens inquiry into shoot-to-kill operations by security forces in the North has now been followed by a similar operation against police intelligence there which appears also to have been an "inside job" by a British intelligence service.
The problem of political control and co-ordination of intelligence services is far greater in large countries with external interests than in small countries like Ireland. The only external intelligence work we have undertaken has been of a diplomatic character: visits by Foreign Affairs staff to Northern Ireland to talk to both unionists and nationalists - but not the IRA.
Unlike the British, we wisely refrained from contacts with the IRA or its political wing, Sinn Féin, until a decade ago, when that organisation finally showed a serious interest in ending its campaign of violence.
By contrast, persistent British intelligence and political contacts with IRA/Sinn Féin up to 1980 seemed to me most ill-judged, encouraging the leaders of that organisation in their delusions that if they went on killing, the British government would eventually withdraw from Northern Ireland. At the same time, the activities of some British intelligence agencies in the North frequently aggravated tensions, often driving nationalists into the arms of the IRA.
These two conflicting approaches by British agencies seemed to reflect inadequate political control of the intelligence "community" - that marvellously inappropriate term used to cover the range of bodies engaged in this work.
The problems such activities raised became evident during the Stalker inquiry, when the attorney-general of the day, Patrick Mayhew, was to decide whether prosecuting some intelligence people who were believed to have behaved improperly would be "in the public interest".
It would have seemed that "public interest" in this case must mean Britain's vital interest in creating conditions in Northern Ireland which would favour peace - interests which would have been served by applying the law impartially to those believed to be guilty of serious offences. Instead, "the public interest" turned out to mean those of the security services, some of whose activities were the subject of that inquiry. The situation in the North was perceptibly aggravated by that decision.
All states tend to be defensive about their army, police and intelligence services. Failure to defend them against criticism or worse could alienate their members, with potentially dangerous implications for security. We in Ireland are not exempt from such attitudes; we are just lucky that because of the small size of our State and of its services, and because the security problems we face have generally been less serious than those facing larger countries, we have had to face these kind of problems less often.
We should therefore be wary of adopting "holier than thou" attitudes - a trap we often tend to fall into in relation to other states. That said, it would clearly be in Britain's interests to minimise those tensions between its security services which ultimately weaken confidence in the rule of law in the United Kingdom.