That is not to make light of the murderous racism of the bombings. The police are right to take seriously the possibility of a sustained campaign of terror. There has clearly been a reaction at some subterranean level to the huge publicity given to the Macpherson report on the killing of Stephen Lawrence. It was no coincidence that the 999 call claiming responsibility for the Brixton bomb was made from the street in which Mr Lawrence died. For all the liberal condemnation of "complacency" about the raw deal suffered by ethnic minorities at the hands of unintentional racism, the real shock of the report came from the daubing of the Stephen Lawrence memorial the next day. Racism has been denied respectability and public expression for a long time, but attitudes of that kind are durable.
The difference between the London nail-bomber and Eric Harris and Dylan Klebold, who went on a killing spree in their Denver high school, is that the British case draws on a pool of racist resentment that underlies large parts of our society. The Race Relations Act took down the "whites only" warnings on For Sale signs, but the signs in people's minds cannot be legislated away so quickly. Education helps but takes time, and even that can feed the resentments it seeks to assuage. Recent evidence confirmed that bad anti-racist teaching is worse than no anti-racist teaching at all. Equally, the moral consensus in the US education system that the Holocaust was uniquely evil seems only to have fed the Hitler-fascination of the gothic counter-culture of Harris and Klebold.
All the same, the nail bombs are more the dying twitches of British racism than evidence of a resurgence. This is not the 1970s, when the National Front was a political force capable of mobilising significant support in elections and big marches in between. The British National Party breakaway in 1982 was the start of a process of fission that leaves the far right utterly disorganised today. The brief election of a BNP councillor in east London four years ago was more the end than the beginning.
The denial of any respectable expression to racism has forced attitudes underground, where they will lie quiescent and eventually die out. In some cases, however, suppression is bound to lead to frustration, paranoia and violence. It is difficult to know whether there is, ultimately, anything that can be done about this. There is an obvious parallel between the psychology of the nail-bombers of London and the pipe-bombers of Columbine High. In both cases the animating force is an incoherent anger, pickled in social isolation. Both cases are quite different from, for example, the terrorist campaigns waged by the IRA before 1997, fought by a group large enough to call itself an army, motivated by ideology and sustained by a community which felt a collective grievance.
The key point about the London bombs is that their maker or makers have shaded so far into the margins of society and sanity that they are indistinguishable from the occasional psychopath who is always with us. There will always be people who lash out; it is a small mercy that, ultimately, the madness of Brixton and Brick Lane does not presage a "race war" or anything like it.