The weekend of violence in the North was an indication of what the future held unless the Belfast Agreement was implemented, the former Taoiseach, Mr Albert Reynolds, warned yesterday.
He said he would be apprehensive about the future of the peace process if all parties failed to make progress next month.
"The IRA ceasefire is still intact, but the reappearance of petrol-bombers and people being dragged off the streets is just a signal of where it is going, and what can happen in the future, if the process is not put together in September."
His concerns follow weekend rioting in Derry and clashes between protesting residents and RUC officers on Belfast's Lower Ormeau Road.
The former Fianna Fail leader said he believed there was evidence of a hardening of the stances within unionism and the Orange Order in recent weeks. He said nationalist residents had traditionally been able to sit down and work out their differences with the Apprentice Boys.
"That appeared to happen last week until, out of the blue, the Apprentice Boys decided they could not resolve their differences. It was the very same as the unionists' rejection of the Good Friday agreement."
Similarly, Saturday's march down the Lower Ormeau Road was the first such in four years.
"These events are indicators to nationalist communities that the other side are going away from reaching understanding and agreement."
In response to this rejection, the petrol-bombs and the sit-down protests were a signal of a return to "old times". He said that he had heard three days previously that petrol-bombs were being prepared.
With the review of the implementation of the Belfast Agreement due to begin next month, Mr Reynolds said, it was difficult to see what changes could take place to bring unionists on board.
Decommissioning remained the sticking point. "Tony Blair and the Taoiseach are satisfied that decommissioning can happen, and the unionists are the only people who believe it cannot happen, but they are not prepared to put it to the test," he said.