Les Rogers, chairman of the Police Federation in Northern Ireland, declared that dismantling the force could "create a blank canvas for new terrorism and disorder to paint murder and mayhem unhindered" in an apocalyptic warning about the intentions of paramilitary groups, the prospects for peace, and the future of the force
Speaking in Plymouth, Mr Rogers echoed Unionist demands for paramilitary arms decommissioning.
His views are seen as a reflection of the widespread unease among police officers, who see an uncertain future in a time of great change in Northern Ireland.
A commission, due to report next year on the future of policing, is widely expected to recommend a significant reduction in RUC numbers.
Mr Rogers, whose federation represents the RUC rank and file, said the IRA ceasefire was holding so far, and that there had been no verifiable IRA bombings or shootings of security-force members.
He added: "Yet Northern Ireland is not a peaceful society. To date this year there have been nearly 55 terrorist-related murders and since 1994 over 1,000 brutal assaults on civilians by paramilitaries.
"There is not so much an unseen war going on but an unacknowledged one, character- ised by a level of violence which rose-coloured glasses are determined to define as peace only because of the contrast with what has gone on before."
Mr Rogers warned that republican and loyalist splinter groups still posed continuing threats.
He also opposed any change to the RUC's name, badge or uniform, declaring: "Attacks on the name, in particular, are really attacks on the very existence of the RUC."
The senior Sinn Fein member, Gerry Kelly, immediately criticised Mr Rogers' speech, saying: "Mr Rogers is engaged in an attempt to maintain a stranglehold on policing here.
"The RUC is clearly incapable of policing in a fair or impartial manner. It must be disbanded and replaced with an unarmed, accountable and community- based policing service."
Mr Rogers' remarks on arms decommissioning, a process which he viewed as essential, will be viewed as valuable support by Unionist politicians, who insist that Sinn Fein cannot be admitted to government unless the IRA begins to disarm.
Few if any politicians, however, share his view that the scene is being set for an arms handover in exchange for RUC disbandment.Reuse content