How far should we be willing to forgive and forget past crimes in the interests of building lasting peace? The issue has been a running sore in Northern Ireland politics despite the Good Friday peace agreement. The Police Service of Northern Ireland has a special unit, the Legacy Investigations Branch, to review more than 3000 murders during the Troubles. But there are allegations it is prioritising re-opening the killings where soldiers from the British Army were involved, over those carried out by terrorists - the majority of which were by Republicans. There are practical issues of getting evidence for crimes that happened so long ago and the cost of investigations, but the moral questions are harder to answer. How do you weigh the right and the need of the families of victims to get justice for their loved ones, against the need to move on and find peace for the whole community? A general amnesty might solve the narrow question, but does that serve the interests of justice? And can you find reconciliation and peace if people feel they've been denied justice? As we move further away from the conflict, does the current generation who lived through it (and in some cases took and active role in it) have a responsibility to set aside their history in the interests of peace for the next generation? These are questions for Northern Ireland, but also around the world - in Cyprus, where there are renewed hopes for a peace deal that can united the island; in Colombia where, in a referendum, the people rejected a peace deal between the government and Farc rebels that would have ended the 52-year-long conflict that has killed more than 220,000 people; and in the Balkans where the truth and reconciliation process is struggling. What price peace? Producer: Phil Pegum.