Last year it looked too easy. By a huge vote, Sinn Fein ditched Articles 2 and 3 of the South's Constitution and agreed to allow its representatives to sit in a Northern Assembly. At the time there were dissidents prowling the land, the activities which led to the Omagh bomb were in train, there were reports that significant elements in the IRA - especially south of the Border - were defecting to the dissident cause.

With hindsight, the media hype did not quite match the reality. The dissidents were recruiting but not in the numbers reported and were shortly to self-destruct with the Omagh disaster. That was not how it seemed at the time and no doubt the Sinn Fein leadership was worried. Republican parties lead a strange double-life, where what happens on the shadowy militarist side can and usually does determine events inside the political organisation.

About a third of the delegates last year voiced strong reservations about the Belfast Agreement and probably voted for it more out of loyalty to the leadership than from conviction.

Less self-restraint is likely this time around. The leadership will not be entirely unhappy, however, to hear expressions of dissent and discontent. Sinn Fein spokesmen frequently note with a touch of envy that Mr David Trimble's greatest strength in the political sphere is, ironically enough, his perceived weakness as leader of the Ulster Unionist Party.

The spokesmen usually make light of Mr Trimble's internal difficulties and then go into a dirge about being taken for granted by the political establishment. So don't expect any great effort to stifle dissent at this weekend's gathering in the RDS.

As it happens, the internal difficulties the republican leadership has to cope with are not insignificant. There are persistent reports of tension between the traditionalist heartland of South Armagh and the more politically-minded elements in West Belfast. It is always necessary also to keep an eye on the Irish-American scene, which tends to unravel faster than the tight-knit and secretive republican community back home.

But even the republican heartlands are volatile at the moment. The fact that the persistent attacks on nationalist homes by loyalist paramilitaries do not attract much media publicity does not mean they have an insignificant impact on the nationalist community in the North, any member of which could be the next target.

The indications of possible movement at Downing Street this week will keep the ardfheis from taking an unduly sour turn. The leadership staked its all on the Belfast Agreement and if it goes, the current leadership team will probably go with it - and the armed campaign will probably be resumed.

The problem for the republican leadership is that a gesture which may be necessary to placate its internal critics does not always play well in the wider world. A typical example was the appearance of the Balcombe Street prisoners at last year's ardfheis. It was an implicit endorsement of the leadership by the hardest of the hard men and one of the results was to reduce dissent to a whisper. But it nearly sank the agreement by scaring off unionist voters. And if the referendum had been lost, or had merely squeaked through, where would the Sinn Fein leadership be now?

The extraordinary fact that Sinn Fein leaders were yesterday walking in the same Downing Street garden where the IRA dropped three mortar bombs eight years ago underlines how much the situation has changed in a very short time.

The nationalist consensus has worked to the benefit of Sinn Fein. Its leaders have better access to the White House than some heads of state. It's a big change from the years of exclusion and poky bar-rooms in the Bronx.

The party is running 130 candidates in the local elections and five for Europe. Its political base in the North is solid and some progress has also been made in the Republic. Mr Gerry Adams was quoted as saying that the IRA probably would have disappeared by now if the 1994 ceasefire had been properly welcomed by London and the unionists - and until the IRA really has gone away, electoral progress in the South is likely to be limited.

That is a pipe-dream to constitutional republicans and democratic nationalists. The withering away of republican militarism will come only with the establishment and consolidation of the institutions in the Belfast Agreement and, at least as important, the inclusion of nationalists on a proportional basis in the police force in Northern Ireland.

There will be a big media presence at this weekend's ardfheis: time was when reporters were reluctant to be seen there lest they be smeared as subversives. Apart from the odd dissenting speech there is likely to be little drama: ritual denunciations of the British and the unionists by the leadership and a fair amount of sniping from the floor at Mr Bertie Ahern for his erratic approach on the issue of a weapons handover. Advocates of IRA decommissioning will be as rare as the proverbial white blackbird.

Ironically, the topics for discussion - environment, health, the European Union - could have come from the conference agenda of any mildly left-wing party. Not for nothing were Sinn Fein and their associates once described as "armed social democrats". The republican movement goes through moderate phases - as at the time of the New Departure with Parnell - and this is one of the most moderate of all.

Last year, Sinn Fein crossed the Rubicon. In the intervening 12 months it has discovered that life on the other side of the river can have its problems. The persistence of these unresolved issues may lead to some fractious moments this weekend but for the Sinn Fein leadership there seems to be no turning back.