`They cannot go on saying No. They must say Yes to something." So said the former Northern Ireland secretary, Tom King, of the unionists in 1986. If unionism is to say Yes - and it is so minded today - the words of John Bruton will have to be heeded. Restraint must be the order of the day from the Republic's mainstream politicians.

It is one of the ironies of political life in Northern Ireland that many are prepared to believe the other side rather than their own leaders.

If the Belfast agreement is to succeed in producing a win-win result for unionists and nationalists - unionists in terms of their constitutional rights being protected, nationalists in terms of their human and cultural rights - a few hurdles in Northern Ireland have to be cleared before the campaign in the Republic can really begin.

It would be unfortunate if a copy of the agreement does not reach every home in the Republic as it contains more obligations than simply to approve the new Articles 2 and 3. There is, for example, a section on steps for the Government in Dublin to take on human rights. Responsible citizens should remind their politicians of these steps.

Not only will the Republic have to take serious note of the Constitution Review Group's report, but it must consider adopting the European Convention on Human Rights into Irish law. Soon the Republic will be the only European country not to adopt the ECHR.

The Irish Government has committed itself to setting up a Human Rights Commission similar to that for Northern Ireland and to ratifying the Council of Europe Framework Convention on National Minorities. It has also promised to implement enhanced employment equality legislation and equal status legislation and to take further steps to demonstrate its respect for Ireland's different traditions.

That includes expressions of the identity of the non-nationalist minority on the island, North and South. A No vote in the Republic is also a vote against these provisions of the agreement.

Not only would unionists never forgive a No in the South, neither would the vast majority of Northern nationalists. De Valera's Articles 2 and 3 do not represent the island of Ireland today; rather an imperative that could never be fulfilled without unionist consent. As Micheal Mac Liammoir once said, "What a paradise Ireland would be if it had as much affection and respect for the living as it has for the dead."

Nationalists in the South cannot force unionists to accept an idea they oppose, nor adopt a badge of nationality they are uncomfortable with. Equally, unionists cannot pretend that Northern nationalists are not Irish, nor that they should accept no input into the governance of Northern Ireland.

The agreement has passed several hurdles in mainstream unionism already. The talks team, the officer hierarchy and the party executive have already cleared it. It has also, perhaps surprisingly, not been rejected out of hand by the Grand Orange Lodge.

The most crucial test comes with tomorrow's Ulster Unionist Council meeting. Rejection of the document will bring this agreement down, and with it, most probably, David Trimble's leadership. His opponents have already rechristened his supporters Trimbleites - rather than the previous Trimbleistas - to match those of Brian Faulkner.

However, this agreement differs significantly from that at Sunning dale, as has unionism. Not only does the new agreement not include an autonomous Council of Ireland but the sense of loss after the fall of Stormont has virtually evaporated.

Unionists and nationalists have become more realistic. Unionists know untrammelled majority rule is not an option; nor is a two-finger approach to North-South co-operation. Nationalists know a North-South element is conditional on removal of the territorial claim.

The unionists calling for a No are already fighting an uphill battle on constitutional issues. Their strength lies in their manipulation of emotions on so-called equality issues, particularly prisoners. They forget, however, that after the IRA's 1956-62 Operation Harvest campaign all the internees were released immediately and the 26 convicted prisoners in jail in February 1962 when the ceasefire was called were all released on licence within 17 months.

The release of prisoners from Portlaoise this week might have helped to secure the position of the Adams leadership, but it impacted negatively on nervous unionists. Another blow before Saturday lunchtime could be fatal.

Currently, many unionist council members are torn between the desire for community solidarity and the dream of breaking the Paisleyite curse once and for all. Travelling outside Northern Ireland with the world believing Ian Paisley is your spiritual and political leader has for 30 years been one of the prices of considering oneself a unionist. His shambolic performance outside the talks venue made unionists laugh and not sympathise, for once. Now only the British and Irish governments can rescue him as they did at Sunningdale for expecting too much from Faulkner and, before him, O'Neill.

If society in the Republic spent more time pondering how Ireland can be managed across two jurisdictions rather than persuading unionists to accept a jurisdiction they have repeatedly spurned, true reconciliation might be advanced. Charles Haughey was right to note that symbolic acts such as the restoration of Islandbridge and the building of an interpretative centre at the Boyne will not make nationalists out of unionists. But it might make true republicans out of militant nationalists.

As soon as the referendum is over, the Forum for Peace and Reconciliation's report on Barriers to Reconciliation in the South must be dusted off. Playing Amrhan na bhFiann at Irish rugby matches must be recognised as an act of provocation rather than reconciliation.

Above all, no fact has armed Paisley more than the dramatic decline of the Protestant population in the Republic. Most of it is explicable through intermarriage and emigration, but it compares with a burgeoning minority population in Northern Ireland.

Who is scared of a Commission on the Status of the Religious Minorities to match the commissions in Northern Ireland on policing, criminal justice and Bloody Sunday? And when is time going to be found in the Southern curriculum for reconciliation studies to prevent another generation in Kerry and Cork hating people they have never met?

Some republicans will say that now unionists have got Articles 2 and 3 they are coming back for more. Far from it. But the mindset which created 2 and 3 must equally be challenged. Otherwise unionists and the IRA will go back to what they know best.

Steven King is a special adviser to Mr John Taylor MP, deputy leader of the UUP