How many exclusion episodes can the Northern Ireland peace process survive? The technicalities of exclusion number two are well under way this morning following the British Government's formal indictment of Sinn Fein because of police forensic evidence which points to IRA culpability in two recent murders. The protestations of innocence and irrelevance from Sinn Fein were angry and prolonged but ultimately fruitless. Spokesmen tried to argue that Sinn Fein was responsible only for Sinn Fein, that it was not politically accountable for the IRA and that there were no organic links between the two organisations. To argue this is to deny recent Irish history, although there is a justifiable element in the proposition that Sinn Fein's successes in elections confirms its representation of a vital and exclusively civilian constituency in the process.

There are grounds for believing that Mr Adams and Mr McGuinness are unhappy with a return to violence by the IRA. Whether either of the men who died had any connection with drugs is irrelevant. Killing people is a denial of the Mitchell Principles and the consequences are clear. The suggestion that the Sinn Fein leadership was looking for a way out of the talks is nonsense. Yet Mr Adams and Mr McGuinness are leaders of the Republican movement and must accept an element of responsibility for its actions, whether they are happy with them or not. It is simply ridiculous of them to try to protest that they are divorced from the IRA. They were admitted to the talks because of the IRA's apparent adherence to a ceasefire and were involved only as long as that ceasefire held.

That said, another expulsion, if it happens, is grievously disappointing and represents a serious blow to a process which was expected to be complete by May. The key to the current process, the shining principle (apart from non-violence) on which it rests, is that of inclusion. The process will work if everyone takes part with as much good faith as they can muster. Exclusion is the direct opposite. We argued at the time of the UDP's expulsion that the party could have remained within the process for the moment. Frankly, it would be better if Sinn Fein remained at the table too, but the thrust of the argument, the imperative which is the only possible result of violence, has gone against this. The UDP went and Sinn Fein must go as well.

The absence of Sinn Fein from the talks will be accompanied by the obvious fear that the IRA will use it as a pretext to take violence further. Whether this will happen is anybody's guess but the time away from the talks must be used in contacts between the British and Irish Governments which are used in a positive and reassuring manner. When, after two or three weeks, Sinn Fein returns it is vital that the principle of inclusion is stressed. This will require Mr

Trimble to talk to Sinn Fein, whatever his backwoodsmen think, and it will require determination and unanimity from the British and Irish Governments as well.