In 1878-79 Parnell presided over the "New Departure"; Irish nationalist politics was remodelled and revitalised under his leadership. In the process, many republicans moved away from a reliance on physical force. Ten years later, Parnell insisted the action of republicans in joining the "constitutionalist" movement was "quite honest . . . that they had no arriere-pensee [ulterior motive] of any sort".

In fact, this claim was only partially true. Some republicans did become unreservedly constitutionalist in the 1890s but most saw the New Departure as a means of pursuing the revolution by other means. They had hoped to exacerbate contradictions within the forces opposed to them - in particular, the contradiction between the British state and the southern unionist landlords - and thus generate an instability favourable to the achievement of traditional Fenian objectives.

The neo-Fenians of 1878-79 had a lot of early success but in the end they guessed wrong. In particular, the British state - contrary to their expectations - had enough reformist capacity to ameliorate the land issue. The constitutionalists remained firmly in the saddle.

Gerry Adams's Irish-American admirers, in particular, have been quick to present his policy since the ceasefire of 1994 as another version of the New Departure. It is therefore worth asking where republicans of today stand.

At the moment there is no mood in the mainstream republican movement for a return to war. But do they perhaps have an arrierepensee?

It is worth pointing out that the Belfast Agreement falls considerably short of Sinn Fein's minimum requirements for a settlement as they have been expressed over the past five years. Above all, Britain has refused to become a persuader for Irish unity; there is nothing inherently transitional about this arrangement.

Republicans may well be willing to make the best of the agreement, warts and all, but if it were destroyed by unionist implosion it would hardly be an unwelcome development. In such a context, they hope the balance of forces would favour an imposed settlement close to joint authority.

Sinn Fein had Mr Trimble on a hook over Drumcree, and they showed no disposition to allow him off it. Last year, Mr Adams called for a ceasefire even after the Orangemen had marched down Garvaghy Road; this he reminded people, reflected his concern for the "bigger picture".

This year the bigger picture did not include - and to be fair, it would have annoyed Mr Adams's electoral base if it had - doing anything to help Mr Trimble. But after the appalling tragedy in Ballymoney, Mr Trimble has survived anyway, though not as he would have wished.

Now there is only one issue likely to cause unionist implosion: decommissioning, perhaps in association with setting up cross-Border bodies and a shadow executive in the autumn. Under the agreement, it is difficult for Republicans to avoid decommissioning within a two-year period, but it is perhaps unlikely, though not impossible, that they will act on a timescale which minimises the contradictions, or genuine fears, within unionism.

But much depends here on unionism's mood and its willingness to impale itself on this issue. The anti-agreement bloc suffered a blow this week but will soon regain its nerve.

Monday was a dreadful day for Jeffrey Donaldson to throw a hint of anti-Trimble realignment. But serious efforts are under way to establish such a new unionist movement. There is no fresh or realistic thinking behind it, as Donaldson's speech starkly revealed, but it appeals to many disconcerted by the agreement.

It was primed this week to seize the emotional advantage - let us not forget that there could have been bloodstained Orange collarettes on the field at Drumcree - but will now have to wait until the autumn for its next opportunity.

One matter should give great concern to pro-agreement forces, including both governments; last week there was no serious policy option which might have eased the difficulty. The proximity talks were never likely to produce a benign result in the necessary time. As one key player put it, matters were in the "lap of the gods". It would be bad politics indeed if the governments, and this includes the First and Deputy First Ministers, were to lose control again.

Nevertheless, Mr Trimble is strengthened. In the days following the Parades Commission's ruling against Orangemen in Portadown, Mr Trimble was under pressure from some supporters to threaten resignation. Only then, it was reasoned, would Mr Blair be forced to allow the Orangemen down Garvaghy Road.

Mr Trimble was willing to point out - accurately - that the crisis threatened the future of the Assembly but he refused to threaten to resign. Instead he sought to work alongside Seamus Mallon and to defuse the crisis.

As events have unfolded, Mr Trimble's course of action has been justified. The image of Northern Ireland Orangemen, and by association unionism, has suffered its heaviest public relations blow yet in the rest of the UK but with the agreement in place, and Mr Trimble and Mr Mallon at the helm, this matters much less than it would otherwise have done. Many unionists inwardly recognise this and heave a sigh of relief.

Where does all this leave the Orange Order? It has taken a battering this week but will reconstruct itself. In a critical moment, the Rev William Bingham found the words which may help make that possible.

Since he won the leadership of the Ulster Unionist Party in 1995, Mr Trimble has talked about re-examining the Orange link. To be frank, this is more likely to change the UUP's relationship with certain types of liberal Protestants than it is to lead to a flood of Catholic applicants. But it is worth noting that the Assembly party is already significantly less Orange than the parliamentary party.

It is worth noting also that Orange influence is slight on key backroom staff in Glengall Street who fought the referendum and election campaigns. It is worth noting above all that even with the Orange link intact, Mr Trimble has dramatically transformed UUP tactics. He will be aware of the dangers of "disrespecting" mainstream Orange/unionist sentiment; the media can afford to sneer at the beliefs and fears of the ordinary Orangeman but the leadership of the UUP can not.

But Mr Trimble can only win if he is in a position to challenge the logic of his rejectionist unionist opponents. The purpose of a new partnership government is not so much better government, though it may be better in some respects, but partnership and inclusiveness itself. It is to provide stability by reducing the sources of easily generated grievance.

The idea is to move away from a context in which political action is dominated by an activist faction - on the one side or the other - trying to organise and rhetorically exploit its own martyrdom and thus inflame the passive majority. This strategy of inclusiveness poses no threat to the reproduction of British identity in Northern Ireland today. The prize after all, if the agreement is fully implemented, is the recognition by nationalist Ireland of the legitimacy of Northern Ireland's place within the UK on the basis of the principle of consent.

Sinn Fein has long hoped to inflict a demoralising blow against the Orange Order. This week the Orange Order, showing its worst side, stumbled blindly into the trap.

But how important is the order today? Despite Sinn Fein rhetoric, it no longer holds the strategic positions in the professions or business; its power resides simply in being - the expression of the resistance of tens of thousands of ordinary Protestant to the claims of Irish nationalism.

The order's future at this level is guaranteed, above all by Sinn Fein. But the wider game goes on elsewhere. The landscape of the new Northern Ireland Bill makes it clear that the ultimate sovereignty of Westminster sovereignty remains undiminished; in doing so, it merely repeats, in admittedly rather more unionist language, the terms of the agreement itself.

Paul Bew lectures in politics at Queen's University, Belfast