WHEN dealing with violent protests on the streets, it is no good getting things half right. After several nights of trouble on the streets of Ferguson, a district of St Louis, in Missouri, the authorities put a new man in charge of policing, a Highway Patrol Captain, Ron Johnson. Key among his credentials was that he was black. The protests were triggered by the fatal shooting of a black teenager, Michael Brown, by a white police officer, Darren Wilson. In Ferguson, 65 per cent of the population is black, but only six per cent of its police force is. Captain Johnson's appointment is not going to change that ratio, but at least he can appeal to the protesters from within their own ranks: "When this is over, I'm going to go into my son's room. My black son. Who wears his pants saggy, his hat cocked to the side, got tattoos on his arms. But that is my baby." The appeal, made in the Greater Grace Church, lacked finesse, but it won over the congregation.

Not so the crowds outside. Another policing decision last weekend was to bring in the National Guard, the first time they have been deployed to deal with unrest in the United States since 1992. The presence on the streets of a highly militarised force was never likely to calm the situation. The protests now are as much about the authorities' reaction as about the original shooting.

The existence of a black President has had a remarkable effect on racial politics in the US, though this cannot be quantified. The black population remains far poorer, on average, than the white. During the latest financial crisis, the average net worth of a white household has fallen from $135,000 to $113,000. Before the crisis, the average worth of a black household was $12,000. Now it is just $5700. In Ferguson, the unemployment rate is nine per cent. Given the town's racial mix, it is likely to follow the national pattern: 5.4 per cent of whites are unemployed, 11.5 per cent of blacks. In such circumstances, the difference between reluctant acceptance of social conditions and angry protest is aspiration. Religion is still strong, but where it failed, materialism filled the void, creating a dangerously unsatisfying set of desires. With the arrival of President Obama came a new political aspiration, but his second term has been troubled and, thanks to the internal battles with obdurate Republicans in the Senate and House of Representatives, much less impressive.

The circumstances surrounding the death of Michael Brown will not be known for certain for some time - though having a police force that is routinely armed was an obvious factor. It is hard to imagine circumstances that will mollify his neighbours, who have interpreted his death as a sign of a lack of respect for people from his background. The presence of pastors and congregation members among the protesters is welcomed, but the authorities must make creative use of them. It should be acknowledged as a positive thing when a community's members stand in solidarity with one of their number. By contrast, TV images of heavily armed troops battling with looters will send the wrong message, and might escalate the violence.