It sums up much about Northern Ireland that the tenth anniversary of the Good Friday agreement will be marked in such a strange fashion. The Unionist community, and especially the Democratic Unionist Party, agree that something that they refer to as the Belfast agreement was reached on April 10, 1998. But they contend that it was a fundamentally flawed accord that was superseded by the far better St Andrew's agreement of 2006 and hence is not worthy of celebration. Almost all nationalists and republicans, by contrast, refer to it as the Good Friday agreement and believe that it is the document on which the present institutional arrangements in Ulster are based (whatever the DUP might assert). It is therefore worth cheering, except that they held their commemoration on March 21, Good Friday this year (although some will do so again today).

It also sums up much about Northern Ireland today that the two sides can hold such contrasting views and yet maintain a political dialogue and partnership. This is because both claims about the past are valid. The fundamental principles of consent, power-sharing and an end to violence are the essence of the Good Friday agreement and remain the core of the astonishing if fragile settlement. The original bargain was, however, lacking in detail in many sensitive areas, and without the backing of the Rev Ian Paisley and his colleagues it had no enduring legitimacy.

These days, happily, the past matters less than the future. The DUP-Sinn Fein pact is a marriage of convenience and not of love. Although it has worked well over the past year, it will soon be sorely tested both by issues that reopen old wounds and by the enforced retirements of Mr Paisley as First Minister and Bertie Ahern as Taoiseach next month. Some of these difficulties are already being rehearsed in public. The attempt to create a commission for the victims of the Troubles and those who survived them has been stalled because the various political parties have different definitions of who a “victim” is. The proposed transfer of authority over policing and justice to the Province is unlikely to occur on the original schedule and has not been helped by a dispute about the efficiency of the Police Service of Northern Ireland between Gerry Adams, who blames it for failings related to three high-profile murders in West Belfast, and Sir Hugh Orde, its commissioner, who regards these accusations as politically motivated.

The relationship between the incoming First Minister and the Deputy First Minister over the next 12 months is thus unlikely to resemble the “Chuckle Brothers” routine that the improbable duo of Mr Paisley and Martin McGuinness managed to pull off. The Executive is unlikely to collapse but the atmosphere will be chillier.

The bigger question is more challenging. Ulster remains a place dominated by the public sector. By instinct, neither the DUP nor Sinn Fein is a free-market political force. Yet if Northern Ireland is to achieve the level of prosperity desirable and if that wealth is to help to ease the sectarian divide still seen in matters as humble as the choice of where to open a bank account or what newspaper to read, then the Province has to become a much more entrepreneurial society. The obvious model is the Republic of Ireland over the past 15 years, but for different reasons both the DUP and Sinn Fein recoil from it. The Ulster that should exist by April 10, 2018, requires each of them to think again.