The world conference on racism in Durban, South Africa - still proceeding as the New Statesman went to press - was always going to be as much about symbols as about practical realities. And as a symbol, America's decision to walk out because the conference dared to discuss Zionism is as telling a symbol as any. As blacks and Arabs (as well as many whites) see it, Israel gets an easy time from Europe and America because of the historical wrongs done to the Jews. Reparation is made not just in the $60bn or so that Jewish Holocaust survivors have received from the German government, or in the likely compensation from the Swiss for looted wealth, but in the American capital that pours into Israel, allowing it to live far beyond its means, notably in defence spending.

So blacks quite naturally wonder why they shouldn't receive at least an apology for slavery, particularly when American Indians, Aborigines, Inuit, Korean comfort women, Irish and others have received various forms of regret, if not much redress, in recent years. Some black American campaigners, such as Randall Robinson, argue that slavery was a worse crime even than the genocides of the 20th century. The Jews, Armenians and Cambodians, says Mr Robinson in a book that has become the bible of the growing US reparations movement, "weathered the savageries with their cultural memories intact" and so could "regenerate themselves and their societies". What was uniquely awful about slavery was that it tore people from their roots and transported them across half the world, asphyxiating memory and smothering culture. It is hard to argue with that. Whatever the precise headcount of death at the time, every African-American and every Afro-Caribbean still suffers in some way from the heritage of slavery, as Darcus Howe suggests on page 22. And at a simpler level, slavery involved the theft of people's labour. That is about as clear-cut a case of criminality as you could want, and millions of blacks now alive are poorer as a direct result.

Comparisons with contemporary slavery are disingenuous. Until the civil war (fought not so much for idealism, as to secure cheap black labour for northern factory owners), American property laws gave legal backing to slavery. In Britain, the government sold licences to run the slave trade. This makes the slavery of American or British history quite distinct from slavery today, which is not usually backed by laws or governments; likewise, apartheid was distinct from the equally obnoxious Indian caste system, which has no standing in the Indian constitution.

So far, so good. But then the practical questions arise. Even if we limit liability to guilty states, do we allow, say, claims from Hungarians against Russia, or from Bangladeshis against Pakistan, or from East Timorese against Indonesia? Do we, for that matter, allow claims by women, both against the discriminatory laws that still exist in Muslim countries and against those that existed in Europe until recently? And can we admit claims for official negligence in fighting discrimination, which might bring contemporary slavery back on the agenda? To list the possibilities is to understand that they could keep every lawyer on the planet in lucrative work for decades. It is hard, in any case, to imagine a court with the power to settle such claims (the proposed international criminal court will have no retrospective jurisdiction).

This is not a question of law, but of political will. In his masterly Microcosmographia Academica, an account of how academic government (for which, read any kind of fusty political process) worked in the 1900s, F M Cornford noted the frequent conservative objection that "one should not act justly now, for fear of raising expectations that one will act still more justly in future". Justice demands that, in Britain and America, every effort is made to outlaw discrimination against blacks and to end their accumulated disadvantages. Likewise, justice demands debt relief for Africa, and opportunities for African countries to sell their goods in the developed world. The word reparations is merely a recognition that these are obligations, not acts of charity.

The Durban conference was preceded by talk of dialogue and empathy. Mary Robinson, the conference secretary-general, has said "we need a catharsis" leading to a coming together of north and south. Many western idealists try to fob black people off with this touchy-feeliness. But Africa is ravaged by war, disease and starvation, and the US inner cities, populated overwhelmingly by blacks, are scarred by drug dependency, gang warfare and poverty. They need help, and they need it now. People who talk about reparations may seem to be off with the fairies, but they are more realistic than those who babble about reconciliation. There will be no reconciliation until white governments and white public opinion unreservedly accept the need for justice.

Colic and the intelligentsia

Motherhood, you may have noticed, is everywhere (even, to forestall any comments about motes and beams, on the cover of last week's New Statesman). Naomi Wolf, in a book serialised in the Guardian, finds that parents with new babies are "exhausted and irritable". Gosh! Rachel Cusk, serialised in the Daily Telegraph, reports that her daughter has colic and, er, cries. Hold the front page! Some may see all this as an example of dumbing-down in the posh papers. Far better, however, to see it as the social and intellectual upgrading of mothers and babies, who have been unmentionable in smart society for too long. For example, novelists and poets (even the women) have been almost wholly silent on these matters, perhaps because the middle classes traditionally subcontracted early child-rearing before packing infants off to boarding school. "This is the way life begins; not with a bang, but a burp." Mock as much as you like, but to many middle-class women, this really is news.