The stakes of Stormont

Well, golly. Northern Ireland's politicians can't agree. Forget Groundhog Day – we've already had our deja vu. And when they can't agree, in fly the British and Irish prime ministers to try to sort things out. And after hours and hours of talks – no deal.

The stakes for this couldn't be higher. Even after all-night talks, Gordon Brown and Brian Cowen had to fess up to no deal. The body language of the two ­leaders and their facial expressions kind of said: what on earth are we going to do with these people?

I guess the last thing Brown wanted this week was a trip to Belfast. Nor Cowen. Does Brown want to re-institute direct rule from London? Hell, no. Does Cowen want a destabilised Northern Ireland on the doorstep of the Republic of Ireland, while he's trying to cope with the strange death of the Celtic tiger economy? Hell, no.

But it just shows how both men and their governments regard this problem as a major issue. For this, if no other ­reason, Northern Ireland's peace process is examined the world over as a model for resolving divided societies. Now, neither prime minister has invested as much time in this as their predecessors, Tony Blair and Bertie Ahern. Do they really be want to be seen to fail? I don't think so.

The prime ministers have said that the prospect of agreement is close to 80%, maybe even more. But we've been here before. The parties involved in Northern Ireland's assembly know that policing and justice powers have to be devolved from London to Belfast. As do Brown and Cowen. Why hasn't it happened? Without going into too much detail, unionists have enough difficulty with Martin McGuinness – a former IRA commander – in government at all, as deputy first minister of the devolved executive, never mind having him run the courts. Tough stuff (for unionists).

What unionists argue is that all the concessions have been in the republicans'/nationalists' favour. What they forget is that the IRA decommissioned its weaponry: and that Sinn Féin signed up to backing policing and justice, and the courts. I suspect that people ­outside of Irish republicanism do not get just how much that was throwing away ­tablets of stone.

The overarching risk in all of this is that Sinn Féin could walk away from the assembly as it stands, and provoke an election where the unionist vote is split three ways – leaving Sinn Féin the largest party, and McGuinness the likely first minister in a new assembly. Picture even the most liberal unionist living with that.

There are a few days left to save this Northern Ireland assembly. If it can't be retrieved, look out for direct rule: or worse – for unionists – joint authority between London and Dublin.

There's an old adage in Northern ­Ireland: every time the unionists walk away from the table, the less there is for them when they come back.

A personal prediction? Some kind of halfway house deal will be done, fairly soon. The parties have invested too much in the process to let it go.

And everyone's fear is this: the ­­republican dissident paramilitaries fill the vacuum. The message to Sinn Féin in their latest attacks (including as nasty and as vicious an attack as I can remember in 30 years, on Peadar Heffron, the Irish-speaking Catholic member of the new police force who encapsulates the province's future) is that politics doesn't work. They forget: violence doesn't work either.

So in terms of preserving devolution, could the stakes be any higher? As one official said to me: "I'm pessimistic, but not without hope."

Denis Murray, a former BBC Ireland correspondent.