The PSNI, backed up by the British army, is preparing for a major security operation at Ardoyne, in north Belfast, on July 12th after the Parades Commission ruled that Orangemen should be allowed parade by the nationalist area next Tuesday.
The Ardoyne shops were the scene of violence, first involving nationalists and Orangemen and their supporters last July 12th, and second - and more fiercely - involving nationalists and British paratroops.
Republican sources say there is even greater danger of trouble this year at Ardoyne shops because some former IRA prisoners who helped to police the scene last year have threatened not to assist this Twelfth, in protest at the jailing of Shankill bomber Seán Kelly.
Republicans such as Sinn Féin MLA Gerry Kelly and Bobby Storey were to the fore last year in preventing the unrest getting out of hand after nationalist protesters attacked the British soldiers who were separating them from the Orange marchers and their loyalist supporters.
Seán Kelly was recently jailed because he was viewed to have breached the terms of his licence granting him early release from prison under the terms of the Belfast Agreement.
"Ex-prisoners are saying why should they bother to get involved in policing the situation this year because of the jailing of Seán Kelly.
It was an insane decision, and the potential is that Ardoyne could be really bad this year," said one republican source.
In recent years the annual Drumcree parade, this Sunday, has passed off relatively peacefully, although there is the usual unpredictability factor surrounding Drumcree and the parades outside Belfast.
