Americans began the summer still celebrating the dawn of a "post-racial" era. They are ending it under no such illusion. The summer of 2009 was all about race, beginning with Republican claims that Sonia Sotomayor, Barack Obama's nominee to the US Supreme Court, was "racist" against whites. Then, just as that scandal was dying down, up popped "the Gates controversy", the furore over the president's response to the arrest of African American academic Henry Louis Gates Jr in his own home. Obama's remark that the police had acted "stupidly" was evidence, according to massively popular Fox News host Glenn Beck, that the president "has a deep-seated hatred for white people".

Obama's supposed racism gave a jolt of energy to the fringe movement that claims he has been carrying out a lifelong conspiracy to cover up his (fictional) African birth. Then Fox News gleefully discovered Van Jones, White House special adviser on green jobs. After weeks of being denounced as "a black nationalist who is also an avowed communist", Jones resigned last Sunday.

The undercurrent of all these attacks was that Obama, far from being the colour-blind moderate he posed as during the presidential campaign, is actually obsessed with race, in particular with redistributing white wealth into the hands of African Americans and undocumented Mexican workers. At town hall meetings across the US in August, these bizarre claims coalesced into something resembling an uprising to "take our country back". Henry D Rose, chair of Blacks For Social Justice, recently compared the overwhelmingly white, often armed, anti-Obama crowds to the campaign of "massive resistance" launched in the late 50s – a last-ditch attempt by white southerners to block the racial integration of their schools and protect other Jim Crow laws. Today's "new era of 'massive resistance'," writes Rose, "is also a white racial project."

There is at least one significant difference, however. In the late 50s and early 60s, angry white mobs were reacting to life-changing victories won by the civil rights movement. Today's mobs, on the other hand, are reacting to the symbolic victory of an African American winning the presidency. Yet they are rising up at a time when non-elite blacks and Latinos are losing significant ground, with their homes and jobs slipping away from them at a much higher rate than from whites. So far, Obama has been unwilling to adopt policies specifically geared towards closing this ever-widening divide. The result may well leave minorities with the worst of all worlds: the pain of a full-scale racist backlash without the benefits of policies that alleviate daily hardships. Meanwhile, with Obama constantly painted by the radical right as a cross between Malcolm X and Karl Marx, most progressives feel it is their job to defend him – not to point out that, when it comes to tackling the economic crisis ravaging minority communities, the president is not doing nearly enough.

For many antiracist campaigners, the realisation that Obama might not be the leader they had hoped for came when he announced his administration would be boycotting the UN Durban Review Conference on racism, widely known as "Durban II". Almost all of the public debate about the conference focused on its supposed anti-Israel bias. When it actually took place in April in Geneva, virtually all we heard about was Iranian president Mahmoud Ahmadinejad's inflammatory speech, which was met with rowdy disruptions, from the EU delegates who walked out, to the French Jewish students who put on clown wigs and red noses, and tried to shout him down.

Lost in the circus atmosphere was the enormous importance of the conference to people of African descent, and nowhere more so than among Obama's most loyal base. The US civil rights movement had embraced the first Durban conference, held in summer 2001, with great enthusiasm, viewing it as the start of the final stage of Martin Luther King's dream for full equality. Though most black leaders offered only timid public criticism of the president's Durban II boycott, the decision was discussed privately as his most explicit betrayal of the civil rights struggle since taking office.

The original 2001 gathering was not all about Israelis v Palestinians, or antisemitism, as so many have claimed (though all certainly played a role). The conference was overwhelmingly about Africa, the ongoing legacy of slavery and the huge unpaid debts that the rich owe the poor.

Holding the 2001 World Conference against Racism in what was still being called "the New South Africa" had seemed a terrific idea. World leaders would gather to congratulate themselves on having slain the scourge of apartheid, then pledge to defeat the world's few remaining vestiges of discrimination – things such as police violence, unequal access to certain jobs, lack of adequate healthcare for minorities and intolerance towards immigrants. Appropriate disapproval would be expressed for such failures of equality, and a well-meaning document pledging change would be signed to much fanfare. That, at least, is what western governments expected to happen.

They were mistaken. When the conference arrived in Durban, many delegates were shocked by the angry mood in the streets: tens of thousands of South Africans joined protests outside the conference centre, holding signs that said "Landlessness = racism" and "New apartheid: rich and poor". Many denounced the conference as a sham, and demanded concrete reparations for the crimes of apartheid. South Africa's disillusionment, though particularly striking given its recent democratic victory, was part of a much broader global trend, one that would define the conference, in both the streets and the assembly halls. Around the world, developing countries were increasingly identifying the so-called Washington Consensus economic policies as little more than a clever rebranding effort, a way for former northern colonial powers to continue to drain the southern countries of their wealth without being inconvenienced by the heavy lifting of colonialism. Roughly two years before Durban, a coalition of developing countries had refused further to liberalise their economies, leading to the collapse of World Trade Organisation talks in Seattle. A few months later, a newly militant movement calling for a debt jubilee disrupted the annual meetings of the World Bank and the International Monetary Fund. Durban was a continuation of this mounting southern rebellion, but it added something else to the mix: an invoice for past thefts.

Although it was true that southern countries owed debts to foreign banks and lending institutions, it was also true that in the colonial period – the first wave of globalisation – the wealth of the north was built, in large part, on stolen indigenous land and free labour provided by the slave trade. Many in Durban argued that when these two debts were included in the calculus, it was actually the poorest regions of the world – especially Africa and the Caribbean – that turned out to be the creditors and the rich world that owed a debt. All big UN conferences tend to coalesce around a theme, and in Durban 2001 the clear theme was the call for reparations. The overriding message was that even though the most visible signs of racism had largely disappeared – colonial rule, apartheid, Jim Crow-style segregation – profound racial divides will persist and even widen until the states and corporations that profited from centuries of state-sanctioned racism pay back some of what they owe.

African and Caribbean governments came to Durban with two key demands. The first was for an acknowledgment that slavery and even colonialism itself constituted "crimes against humanity" under international law; the second was for the countries that perpetrated and profited from these crimes to begin to repair the damage. Most everyone agreed that reparations should include a clear and unequivocal apology for slavery, as well as a commitment to returning stolen artefacts and to educating the public about the scale and impact of the slave trade. Above and beyond these more symbolic acts, there was a great deal of debate. Dudley Thompson, former Jamaican foreign minister and a longtime leader in the Pan-African movement, was opposed to any attempt to assign a number to the debt: "It is impossible to put a figure to killing millions of people, our ancestors," he said. The leading reparations voices instead spoke of a "moral debt" that could be used as leverage to reorder international relations in multiple ways, from cancelling Africa's foreign debts to launching a huge develop­ ment programme for Africa on a par with Europe's Marshall Plan. What was emerging was a demand for a radical New Deal for the global south.

African and Caribbean countries had been holding high-level summits on reparations for a decade, with little effect. What prompted the Durban breakthrough was that a similar debate had taken off inside the US. The facts are familiar, if commonly ignored. Even as individual blacks break the colour barrier in virtually every field, the correlation between race and poverty remains deeply entrenched. Blacks in the US consistently have dramatically higher rates of infant mortality, HIV infection, incarceration and unemployment, as well as lower salaries, life expectancy and rates of home ownership. The biggest gap, however, is in net worth. By the end of the 90s, the average black family had a net worth one eighth the national average. Low net worth means less access to traditional credit (and, as we'd later learn, more sub-prime mortgages). It also means families have little besides debt to pass from one generation to the next, preventing the wealth gap closing on its own.

In 2000, Randall Robinson published The Debt: What America Owes To Blacks, which argued that "white society… must own up to slavery and acknowledge its debt to slavery's contemporary victims". The book became a national bestseller, and within months the call for reparations was starting to look like a new anti-apartheid struggle. Students demanded universities disclose their historical ties to the slave trade, city councils began holding public hearings on reparations, chapters of the National Coalition of Blacks for Reparations in America had sprung up across the country and Charles Ogletree, the celebrated Harvard law professor (and one of Obama's closest mentors), put together a team of all-star lawyers to try to win reparations lawsuits in US courts.

By spring 2001, reparations had become the hot-button topic on US talkshows and op-ed pages. And though opponents consistently portrayed the demand as blacks wanting individual handouts from the government, most reparations advocates were clear they were seeking group solutions: mass scholarship funds, for instance, or major investments in preventive healthcare, inner cities and crumbling schools. By the time Durban rolled around in late August, the conference had taken on the air of a black Woodstock. Angela Davis was coming. So were Jesse Jackson and Danny Glover. Small radical groups such as the National Black United Front spent months raising money to buy hundreds of plane tickets to South Africa. Activists travelled to Durban from 168 countries, but the largest delegation by far came from the US: approximately 3,000 people, roughly 2,000 of them African Americans. Ogletree pumped up the crowds with an energetic address: "This is a movement that cannot be stopped… I promise we will see reparations in our lifetime."

The call for reparations took many forms, but one thing was certain: antiracism was transformed in Durban from something safe and comfortable for elites to embrace into something explosive and potentially very, very costly. North American and European governments, the debtors in this new accounting, tried desperately to steer the negotiations on to safe terrain. "We are better to look forward and not point fingers backward," national security adviser Condoleezza Rice said. It was a losing battle. Durban, according to Amina Mohamed, chief negotiator for the Africa bloc, was Africa's "rendezvous with history".

Not everyone was willing to show up for the encounter, however, and that is where the Israel controversies come in. Durban, it should be remembered, took place in the aftermath of the collapse of the Oslo Accords, and there were those who hoped the conference could somehow fill the political vacuum. Six months before the meeting in Durban, at an Asian preparatory conference in Tehran, a few Islamic countries requested language in their draft of the Durban Declaration that described Israeli policies in the occupied territories as "a new kind of apartheid" and a "form of genocide". Then, a month before the conference, there was a new push for changes: references to the Holocaust were paired with the "ethnic cleansing of the Arab population in historic Palestine", while references to "the increase in antisemitism and hostile acts against Jews" were twinned with phrases about "the increase of racist practices of Zionism", and Zionism was described as a movement "based on racism and discriminatory ideas".

There were cases to be made for all of it, but this was language sure to tear the meeting apart (just as "Zionism equals racism" resolutions had torn apart UN gatherings before). Meanwhile, as soon as the conference began, the parallel forum for non-governmental organisations began to spiral out of control. With more than 8,000 participants and no ground rules to speak of, the NGO forum turned into a free-for-all, with, among other incidents, the Arab Lawyers Union passing out a booklet that contained Der Stürmer–style cartoons of hook-nosed Jews with bloody fangs.

High-profile NGO and civil rights leaders roundly condemned the antisemitic incidents, as did Mary Robinson, then UN high commissioner for human rights. None of the controversial language about Israel and Zionism made it into the final Durban Declaration. But for the newly elected administration of George W Bush, that was besides the point. Already testing the boundaries of what would become a new era of US unilateralism, Bush latched on to the gathering's alleged anti-Israel bias as the perfect excuse to flee the scene, neatly avoiding the debates over Israel and reparations. Early in the conference, the US and Israel walked out.

Despite the disruptions, Africa was not denied its rendezvous with history. The final Durban Declaration became the first document with international legal standing to state that "slavery and the slave trade are a crime against humanity and should always have been so, especially the transatlantic slave trade". This language was more than symbolic. When lawyers had sought to win slavery reparations in US courts, the biggest barrier was always the statute of limitations, which had long since expired. But if slavery was "a crime against humanity", it was not restricted by any statute.

On the final day of the conference, after Canada tried to minimise the significance of the declaration, Amina Mohamed, now a top official in the Kenyan government, took the floor in what many remember as the most dramatic moment of the gathering. "Madame President," Mohamed said, "it is not a crime against humanity just for today, nor just for tomorrow, but for always and for all time. Nuremberg made it clear that crimes against humanity are not time-bound." Any acts that take responsibility for these crimes, therefore, "are expected and are in order". The assembly hall erupted in cheers and a long standing ovation.

Groups of African American activists spent their last day at the conference planning a "Millions for Reparations" march on Washington. Attorney Roger Wareham, co-counsel on a high-profile reparations lawsuit and one of the organisers, recalled that as they left South Africa, "people were on a real rolling high" – ready to take their movement to the next level.

That was 9 September 2001. Two days later, Africa's "rendezvous with history" was all but forgotten. The profound demands that rose up from Durban during that first week of September 2001 – for debt cancellation, for reparations for slavery and apartheid, for land redistribution and indigenous land rights, for compensation, not charity – have never again managed to command international attention. At various World Bank meetings and G8 summits there is talk, of course, of graciously providing aid to Africa and perhaps "forgiving" its debts. But there is no suggestion that it might be the G8 countries that are the debtors and Africa the creditor. Or that it is we, in the west, who should be asking forgiveness.

Because Durban disappeared before it had ever fully appeared, it's sometimes hard to believe it happened at all. As Bill Fletcher, author and long-time advocate for African rights, puts it: "It was as if someone had pressed a giant delete button."

When news came that the Durban follow-up conference would take place three months into Obama's presidency, many veterans of the first gathering were convinced the time had finally come to restart that interrupted conversation. And at first the Obama administration seemed to be readying to attend, even sending a small delegation to one of the preparatory conferences. So when Obama announced that he, like Bush before him, would be boycotting, it came as a blow. Especially because the state department's official excuse was that the declaration for the new conference was biased against Israel. The evidence? That the document – which does not reference Israel once – "reaffirms" the 2001 Durban Declaration. Never mind that that was so watered down that Shimon Peres, then Israel's foreign minister, praised it at the time as "an accomplishment of the first order for Israel" and "a painful comedown for the Arab League".

When disappointed activists reconvened for the Durban Review Conference this April, talk in the corridors often turned to the unprecedented sums governments were putting on the line to save the banks. Roger Wareham, for instance, pointed out that if Washington can find billions to bail out AIG, it can also say, "We're going to bail out people of African descent because this is what's happened historically." It's true that, at least on the surface, the economic crisis has handed the reparations movement some powerful new arguments. The hardest part of selling reparations in the US has always been the perception that something would have to be taken away from whites in order for it to be given to blacks and other minorities. But because of the broad support for large stimulus spending, there is a staggering amount of new money floating around – money that does not yet belong to any one group.

Obama's approach to stimulus spending has been rightly criticised for lacking a big idea – the $787bn package he unveiled shortly after taking office is a messy grab bag, with little ambition actually to fix any one of the problems on which it nibbles. Listening to Wareham in Geneva, it occurred to me that a serious attempt to close the economic gaps left by slavery and Jim Crow is as good a big stimulus idea as any.

What is tantalising (and maddening) about Obama is that he has the skills to persuade a great many Americans of the justice of such an endeavour. The one time he gave a major campaign address on race, prompted by controversy over the Reverend Jeremiah Wright, he told a story about the historical legacies of slavery and legalised discrimination that have structurally prevented African Americans from achieving full equality, a story not so different from the one activists such as Wareham tell in arguing for reparations. Obama's speech was delivered six months before Wall Street collapsed, but the same forces he described go a long way toward explaining why the crash happened in the first place: "Legalised discrimination… meant that black families could not amass any meaningful wealth to bequeath to future generations," Obama said, which is precisely why many turned to risky sub-prime mortgages. In Obama's home city of Chicago, black families were four times more likely than whites to get a sub-prime mortgage.

The crisis in African American wealth has only been deepened by the larger economic crisis. In New York City, for instance, the unemployment rate has increased four times faster among blacks than among whites. According to the New York Times, home "defaults occur three times as often in mostly minority census tracts as in mostly white ones". If Obama traced the Wall Street collapse back to the policies of redlining and Jim Crow, all the way to the betrayed promise of 40 acres and a mule for freed slaves, a broad sector of the American public might well be convinced that finally eliminating the structural barriers to full equality is in the interests not just of minorities but of everyone who wants a more stable economy.

Since the economic crisis hit, John A Powell and his team at the Kirwan Institute for the Study of Race and Ethnicity at Ohio State University have been engaged in a project they call "Fair Recovery". It lays out exactly what an economic stimulus programme would look like if eliminating the barriers to equality were its overarching idea. Powell's plan covers everything from access to technology to community redevelopment. A few examples: rather than simply rebuilding the road system by emphasising "shovel ready" projects (as Obama's current plan does), a "fair recovery" approach would include massive investments in public transport to address the fact that African Americans live farther away than any other group from where the jobs are. Similarly, a plan targeting inequality would focus on energy-efficient home improvements in low-income neighbourhoods and, most importantly, require that contractors hire locally. Combine all of these targeted programmes with real health and education reform and, whether or not you call it "reparations", you have something approaching what Randall Robinson called for in The Debt: "A virtual Marshall Plan of federal resources" to close the racial divide.

In his Philadelphia "race speech", Obama was emphatic that race was something "this nation cannot afford to ignore"; that "if we simply retreat into our respective corners, we will never be able to come together and solve challenges like healthcare, or education, or the need to find good jobs for every American". Yet as soon as the speech had served its purpose (saving Obama's campaign from being engulfed by the Wright scandal), he did simply retreat. And his administration has been retreating from race ever since.

Public policy activists report that the White House is interested in hearing only about projects that are "race neutral" – nothing that specifically targets historically disadvantaged constituencies. Its housing and education programmes do not tackle the need for desegregation; indeed Obama's enthusiasm for privately-run "charter" schools may well deepen segregation, since charters are some of the most homogenous schools in the country. When asked specific questions about what his administration is doing to address the financial crisis's wildly disproportionate impact on African Americans and Latinos, Obama has consistently offered a variation on the line that, by fixing the economy and extending benefits, everyone will be helped, "black, brown and white", and the vulnerable most of all.

All this is being met with mounting despair among inequality experts. Extending unemployment benefits and job retraining mainly help people who've just lost their jobs. Reaching those who have never had formal employment – many of whom have criminal records – requires a far more complex strategy that takes down multiple barriers simultaneously. "Treating people who are situated differently as if they were the same can result in much greater inequalities," Powell warns. It will be difficult to measure whether this is the case because the White House's budget office is so far refusing even to keep statistics on how its programmes affect women and minorities.

There were those who saw this coming. The late Latino activist Juan Santos wrote a much-circulated essay during the presidential campaign in which he argued that Obama's unwillingness to talk about race (except when his campaign depended upon it) was a triumph not of post-racialism but of racism, period. Obama's silence, he argued, was the same silence every person of colour in America lives with, understanding that they can be accepted in white society only if they agree not to be angry about racism. "We stay silent, as a rule, on the job. We stay silent, as a rule, in the white world. Barack Obama is the living symbol of our silence. He is our silence writ large. He is our Silence running for president." Santos predicted that "with respect to Black interests, Obama would be a silenced Black ruler: A muzzled Black emperor."

Many of Obama's defenders responded angrily: his silence was a mere electoral strategy, they said. He was doing what it took to make racist white people comfortable voting for a black man. All that would change, of course, when Obama took office. What Obama's decision to boycott Durban demonstrated definitively was that the campaign strategy is also the governing strategy.

Two weeks after the close of the Durban Review Conference, Rush Limbaugh sprang a new theory on his estimated 14 million listeners. Obama, Limbaugh claimed, was deliberately trashing the economy so he could give more handouts to black people. "The objective is more food stamp benefits. The objective is more unemployment benefits. The objective is an expanding welfare state. The objective is to take the nation's wealth and return it to the nation's 'rightful owners'. Think reparations. Think forced reparations here, if you want to understand what actually is going on."

It was nonsense, of course, but the outburst was instructive. No matter how race-neutral Obama tries to be, his actions will be viewed by a large part of the country through the lens of its racial obsessions. So, since even his most modest, Band-Aid measures are going to be greeted as if he is waging a full-on race war, Obama has little to lose by using this brief political window actually to heal a few of the country's racial wounds.

• A longer version of this article appears in the September issue of Harper's Magazine.

Naomi Klein is an award-winning journalist and syndicated columnist and the author of the international and New York Times bestseller The Shock Doctrine: The Rise of Disaster Capitalism, now out in paperback. Her earlier books include the international best-seller, No Logo: Taking Aim at the Brand Bullies (which has just been re-published in a special 10th Anniversary Edition); and the collection Fences and Windows: Dispatches from the Front Lines of the Globalization Debate (2002). To read all her latest writing visit www.naomiklein.org. You can follow her on Twitter: @NaomiAKlein.

more Naomi Klein