As a new history of the Police Federation of Northern Ireland is published, Terry Spence, the federation's chair, has issued a timely reminder of how politicising policing undermined support for law and order in the past.
There is a danger that it could happen again. In his 1999 report on policing, Chris (now Lord) Patten made it very clear that a unionist sense of ownership of the RUC and a nationalist sense of alienation convinced him that change of name and symbols was necessary for a new beginning.
He recounts how opinion polls showed satisfaction ratings of between 65% and 70%, high by European standards, with the RUC's performance on specific criteria. It was higher (80%) among Protestants than Catholics (50%), but the real difference came between the two communities' attitude to the RUC as an institution.
In focus groups, Patten told how working-class Protestants, initially critical of specific police action, closed ranks around the RUC, when a speaker referred to them as 'our' police.
There was also a sense among some unionists that the RUC was letting the side down if it did not support their cause. "When your homes are attacked, don't come crying to me. You will reap what you sow," Ian Paisley told officers who ejected him from Stormont when the then-Assembly was dissolved in 1986.
The idea that the force was there to enforce the law in a neutral fashion was absent. It was expected, in crunch situations, to take a side.
Nationalists, for their part, reacted against the police and, partly due to IRA intimidation and partly due to a feeling that it was not for them, few joined.
Nowadays, dissidents single out Catholic officers for attack to deter recruitment and make the PSNI a less-representative force, which can be isolated and demonised within nationalist communities.
The Patten settlement, at great financial and emotional cost, got the police to a point where it is roughly representative of the community, with around 30% of Catholics in its ranks.
There are also a number of institutions, ranging from the all-party Policing Board and the Police Ombudsman, holding the police to account and ensuring fair play. Dr Michael Maguire, the new Ombudsman, is not from a policing background and his appointment commanded cross-party support. It is important that politicians do not undermine this vital progress. For instance, politicians polarised around the PSNI's response and senior officers' analysis after they enforced a Parades Commission ruling in Ardoyne. When police officers carried out raids during an investigation of Republican Action Against Drugs (RAAD) vigilantes, Sinn Fein hit the roof because the mayor of Derry's home had been raided. The DUP called for more raids. It would have inspired more confidence if the mayor had swallowed hard and said he was happy to co-operate with the police and that, since he supported them in combating RAAD, the search had been pointless.
The two big parties might have done better to have focused on the fight against RAAD, leaving it to the Chief Constable to decide tactics and the Ombudsman to investigate complaints.