Is it necessary publicly to confront and exorcise the crimes of the past in order to build a peace that is capable of enduring for future generations? The question is raised in the most stark way by the levels of sectarian hatred manifested in parts of Belfast in recent days.
John Reid, the Northern Ireland Secretary, is keen to emphasise that the North has made great progress over the past decade. He is right to remind us that it is still less than 10 years since the first IRA ceasefire.
But Northern Irish politicians, who have an intimate knowledge of their own communities, are deeply worried about the murderous hostility which is now evident on both sides.
There are two schools of thought - and many sub-divisions - on how this problem, which becomes even more dangerous as the marching season approaches, should be addressed.
Some of those who have been involved in dealing with the legacy of bitterness left by 30 years of violence, believe that, sooner or later, Northern Ireland will have to follow the example of South Africa.
They argue that some form of public tribunal, along the lines of the Truth and Reconciliation Commission, is necessary to enable both communities to experience the healing power of truth.
Others, equally committed to building a lasting peace, are opposed to this idea. They dismiss "the reconciliation industry" as a stratagem designed to find scapegoats for the violence which occurred during the Troubles.
The leadership of Sinn Féin believes that it is not yet possible to examine what happened during 30 years of conflict without reopening dangerous wounds. Far better, it argues, to build on the Belfast Agreement, to demonstrate to republicans and loyalists alike that politics is the engine which will create mutual trust.
In the past I've found this to be a persuasive argument. But there is one serious problem - it isn't working.
Senior police officers have warned that Northern Ireland is "sleepwalking towards the abyss". Part of the problem, of course, is that we have become so accustomed to this kind of language that it is all too easy to ignore it.
I don't want to undervalue the work which has been done by many good people in Northern Ireland to try and bridge the divide. What is still lacking is a serious public debate on how the history of 30 years can be examined in a way which will allow both communities to put it behind them.
Last month, in the hope of learning from the experience of others, I went to a talk given in Dublin by the British historian Antony Beevor. His book, Berlin - The Downfall 1945, heads the bestseller lists here and in Britain. Many readers, like myself, will have bought it because of what they learnt about man's inhumanity - and occasional compassion - to man in the author's epic narrative Stalingrad.
Beevor's new book is the story of the Russians' campaign to reach the German capital before the British and US armies. Already reviewed in this newspaper by Kevin Myers, this is a terrible story of cruelty and revenge, illumined by some incidents of heroic pity and generosity.
The most chilling aspect of the Soviet army's vengeance for Hitler's war on the Eastern Front was its treatment of women. It is estimated that over two million women - mainly German but also Polish, Lithuanian, Russian slave labourers and Jews - were raped, often repeatedly, during the conquering army's advance on Berlin. With a very few exceptions, these acts were condoned by Russian officers.
During his lecture in Dublin, Beevor spoke of the contrast between Germany and Russia in dealing with this period of their histories.
After the war, very many Germans claimed to be wholly ignorant of the Holocaust. US and British military officials claimed to be "completely flabbergasted" at the extent of the national denial. But in later years, every German child has been taught about the systematic destruction of the Jews. There may be those who do not believe it, but that is not for want of effort on the part of successive German governments.
Why is it that the issue of the Soviet army's conduct has never been subjected to the same scrutiny within Russia? Even today, Russian historians describe the mass rapes as "negative phenomena in the liberation army".
Beevor points to the fact that post-war Germany enjoyed great success economically, but also in the way it developed as a democracy. This, he suggests, gave people the emotional space to come to terms with an appalling history.
In Russia, which experienced no such benefits, the war was and is regarded as sacred. He was told by one senior official "the great sacrifice is not open to any criticism".
I am not attempting to equate the horrors perpetrated by two totalitarian regimes in the second World War with what happened during 30 years of violence in Northern Ireland. That would verge on the obscene. But there are lessons to be learnt about the huge problem of confronting the past and the absolute necessity of doing so.
Many people who were involved in the peace process are confident that there will be no return to the bad old days of violence in Northern Ireland. I hope and pray that they are right. At the same time the lessons of history, as well as the scenes on the streets of east Belfast, teach us that we would be very foolish to feel complacent.