Lurgan riot is yet another warning sign
British Prime Minister Harold Macmillan, when asked what trigger propelled politics, replied: "Events, dear boy. Events." The aphorism applies as well today in Northern Ireland as it did in Macmillan's Britain of the 1950s and 1960s. Events, as was apparent in Lurgan and Armagh on Tuesday night, have a habit of running away with themselves.
At Castle Buildings in Stormont it is difficult to predict if unionist and nationalist politicians are capable of striking a deal. But outside, the climate is equally unpredictable and, more worryingly, incendiary.
What happened in Lurgan and Armagh reflects an underlying tension that is pervasive. While the talks plod on there is anxiety that some unexpected happening will destroy all hope of progress and send each side scuttling back to the trenches.
The sight of armed and masked men in paramilitary uniform, of blazing buses silhouetted against a night sky, of youths running amok and more senior confederates dictating events from the shadows, was a chastening corrective to any thoughts of the peace process proceeding smoothly to a successful conclusion.
There are grounds for concern: Sinn Fein members are resigning in Co Louth; senior IRA figures are leaving the organisation; there's more rumbling in south Armagh; the Continuity IRA, the Loyalist Volunteer Force and the INLA still pose a serious threat; there are mutterings from the UVF and UDA.
Sinn Fein complains daily of a heavy-handed security presence in west Belfast, south and north Armagh, and other nationalist areas. This time, though, it is not alone in its criticism. Fairly moderate SDLP politicians are using the phrase coined by Sinn Fein: the British government is following an agenda laid down by the "securocrats", they claim.
While Tuesday's disturbances ostensibly derive from a local issue, the recent arrests and alleged RUC harassment of Lurgan republican Mr Colin Duffy, they also serve as a warning of the dangers of trouble spilling into other areas.
Based on reliable local and political sources, there is little doubt that Mr Duffy and his family have been the subjects of persistent questioning and arrests by the RUC. Police have failed to convict him on a number of serious charges, including murder, and some officers seem determined to make his life as difficult as possible.
Equally, there is little doubt that, in response, local republicans orchestrated a considerable degree of the trouble. As was demonstrated when Lee Clegg was released, it is an extreme form of civil protest which republicans can generally regulate.
Republicans argue that such street violence can be a safety valve for expressions of local anger and disaffection. But, against the current background, this strategy has inherent dangers. While hitherto republicans could shape such events to their advantage, they now have the potential to get out of control.
Republicans have already signalled that they are about to embark on a period of civil demonstrations in order to highlight the issues of prisoners and the lack of movement in the talks process. This will involve street protests which, again, will heighten tensions.
Sinn Fein's chief negotiator, Mr Martin McGuinness, raised republican concerns with the North's Security Minister, Mr Adam Ingram, yesterday. Previously the party's leader, Mr Gerry Adams, said he had been told by a senior NIO official that there would be no scaling down of security activity.
An imminent decision to withdraw several hundred soldiers may be Britain's first response to the complaints, and an implicit acknowledgement that, in unpredictable times, it is wise not to allow events get out of control.