Why did it happen?

I've had my say about the causes of the recent street riots, but it's interesting to see what the politicians are making of it.  David Cameron sees it as evidence of a general "moral decline", Ed Miliband says it is all down to "social deprivation" whereas Tony Blair blames specific families who, as he sees it, have deliberately chosen to live "outside the pale".  I think that Cameron and Blair are in fact saying much the same thing in two different ways, whereas Miliband is simply trotting out the traditional Labour line that anything bad must be the result of social inequality.  The problem with the Cameron/Blair argument is that it presupposes that there is such a thing as morality (Cameron) or defined norms of behaviour (Blair).  We last seriously had this argument in the late 50s over the question of whether to decriminalise homosexual activity between consenting adults.  Lord Devlin (the most articulate Law Lord there's ever been) and Professor Hart slugged it out in print, and the generally accepted outcome was that there was really no such thing as a completely shared morality or any fundamentally accepted ways of behaving, and that there will always be those who see things differently.  Of course, how they choose to express their "difference" is what is at the root of the problem.