So there's the answer: fear. Forget about respect and rehabilitation. Dismiss talk of being tough on the causes of crime. Just put the fear of death into the louts and rioters.
Speaking in New York, Mr Bratton, 63, said police forces should be more assertive in their dealings with offenders, leaving no doubt that crime would always meet a firm response.
“You want the criminal element to fear them, fear their ability to interrupt their own ability to carry out criminal behaviour, and arrest and prosecute and incarcerate them,” he said.
“In my experience, the younger criminal element don’t fear the police and have been emboldened to challenge the police and effectively take them on.”
You can of course take it too far - look at President Assad of Syria. But I am sure, I think, that Generalissimo Cameron knows where to draw the line. He does, doesn't he?