The Ardoyne clashes typically have persisted for two or three nights and involved the burning of hijacked vehicles, the hurling of homemade grenades and bursts of gunfire from IRA members. More than 250 police officers have been injured there in Twelfth-inspired violence since 2009.
The recurring conflict demonstrates how IRA splinter groups remain active despite the 2005 decision of most IRA members to disarm and officially abandon their 1970-1997 campaign to force Northern Ireland out of the UK.
This year for the first time, the Parades Commission has ordered Orangemen to avoid the main road beside Ardoyne. However, the Orangemen have no logical alternative route to their lodge in a nearby district, and Protestants are threatening to stand their ground until police let them through.
Orange leaders dismissed concerns that their plan for late-night standoffs with police could easily spiral out of control.