"NO ceasefire! No ceasefire!" yelled a youth at the Garvaghy Road in Portadown yesterday as residents bombarded the RUC and British army with bricks and bottles.
All over the North the feeling among republicans and nationalists generally is hardening.
"There are a lot of people who even vote SDLP who would support IRA retaliation over the next few days," claimed a republican source in West Belfast.
"Our own base is itching for a go at the Brits and the RUC. All their frustration and anger at the peace process is boiling over. Volunteers on the ground want action."
Sinn Fein leaders have cooler beads, but even they cannot disguise their dismay at the decision to allow the Orangemen down the Garvaghy Road. They had genuinely believed until the last minute that the march would be re- routed.
One senior Sinn Fein politician, in ardent supporter of the peace process, admitted that it seemed to be dead. "All the pillars of the Northern Ireland State - the Orange Order, the RUC and the Unionist Party - have united against the nationalist community," he said.
A Sinn Fein ardcomhairle member said that what was most depressing was that the combined strength of the SDLP, the Government and republicans was not enough to influence the British government. He agreed that the Taoiseach, Mr Ahern, had done everything possible. "The Anglo-Irish Agreement now seems totally worthless," he said.
However, he added, Sinn Fein would be attempting to rebuild the peace process. "We do not have the luxury of walking away from the peace process. The alternative would be only another 25 years of conflict," he said.
But a West Belfast dissident said that militants would do everything possible to undermine the peace strategy.
Sinn Fein speedily held a protest march in West Belfast yesterday, and further rallies will take place this week. Mr Gerry Adams is keen to channel grassroots energy into these demonstrations and to take the heat out of the situation.
Most observers believe that an IRA response to Garvaghy Road is inevitable.
The scale of the retaliation seems to be the only question.
Mr Gerry Adams's hand has been weakened by yesterday's events, but it remains to be seen by how much. He will be hoping that the British government bans Saturday's march on the Ormeau Road in Belfast.
That could be a small step towards easing the anger of republican grassroots and retrieving his position, Any Sinn Fein leader currently suggesting another IRA ceasefire would be given short shrift, to say the least, in Twinbrook, Lenadoon or Ardoyne.