If we are to believe the G7 finance ministers, Haiti is on its way to getting something it has deserved for a very long time: full "forgiveness" of its foreign debt. In Port-au-Prince, Haitian economist Camille Chalmers has been watching these developments with cautious optimism. Debt cancellation is a good start, he told al-Jazeera English, but: "It's time to go much further. We have to talk about reparations and restitution for the devastating consequences of debt." In this telling, the whole idea that Haiti is a debtor needs to be abandoned. Haiti, he argues, is a creditor – and it is we, in the west, who are deeply in arrears.

Our debt to Haiti stems from four main sources: slavery, the US occupation, dictatorship and climate change. These claims are not fantastical, nor merely rhetorical. They rest on multiple violations of legal norms. Here, far too briefly, are highlights of the Haiti case.

The slavery debt. When Haitians won their independence from France in 1804, they had every right to claim reparations from the powers that had profited from three centuries of stolen labour. France, however, was convinced that it was Haitians who had stolen the property of slave owners, by refusing to work for free. So in 1825, with a flotilla of warships stationed off the Haitian coast threatening to re-enslave the former colony, King Charles X came to collect 90m gold francs – 10 times Haiti's annual revenue at the time. With no way to refuse, and no way to pay, the young nation was shackled to a debt that would take 122 years to pay off.

In 2003, Haitian president Jean-Bertrand Aristide, facing a crippling economic embargo, announced that Haiti would sue the French. "Our argument," Aristide's former lawyer Ira Kurzban told me, "was that the contract was an invalid agreement because it was based on the threat of re-enslavement at a time when the international community regarded slavery as an evil." The French government was sufficiently concerned that it sent a mediator to Port-au-Prince to keep the case out of court. In the end, however, its problem was eliminated: Aristide was toppled from power. The lawsuit disappeared, but for many Haitians the reparations claim lives on.

The dictatorship debt. From 1957 to 1986, Haiti was ruled by the defiantly kleptocratic Duvalier regime. Unlike the French debt, the case against the Duvaliers made it into several courts, which traced Haitian funds to an elaborate network of Swiss bank accounts and lavish properties. In 1988 Kurzban won a landmark suit against Jean-Claude "Baby Doc" Duvalier when a US district court in Miami found that the deposed ruler had "misappropriated more than $504,000,000 from public monies".

Haitians, of course, are still waiting for their payback – but that was only the beginning of their losses. For more than two decades, the country's creditors insisted that Haitians honour the huge debts incurred by the Duvaliers, estimated at $844m, much of it owed to institutions like the IMF and the World Bank. In debt service alone, Haitians have paid out tens of millions every year.

Was it legal for foreign lenders to collect on the Duvalier debts when so much of it was never spent in Haiti? Very likely not. As Cephas Lumina, the UN independent expert on foreign debt, put it to me: "The case of Haiti is one of the best examples of odious debt in the world. On that basis alone the debt should be unconditionally cancelled." But even if Haiti does see full debt cancellation (a big if), that does not extinguish its right to be compensated for debts already collected.

The climate debt. Championed by several developing countries at the climate summit in Copenhagen, the case for climate debt is straightforward. Wealthy countries that have so spectacularly failed to address the climate crisis owe a debt to the developing countries that have done little to cause the crisis, but are disproportionately facing its effects. In short, the polluter pays. Haiti has a particularly compelling claim. Its contribution to climate change has been negligible; Haiti's per capita CO 2 emissions are just 1% of US emissions. Yet Haiti is among the hardest hit countries.

Haiti's vulnerability to climate change is not only – or even mostly – because of geography. It is Haiti's weak infrastructure that turns challenges into disasters, and disasters into catastrophes. The earthquake, though not linked to climate change, is a prime example. And this is where all those debt payments may yet extract their most devastating cost. Each payment to a foreign creditor was money not spent on a road, a school, an electrical line. And that same illegitimate debt empowered the IMF and World Bank to attach onerous conditions to each new loan, requiring Haiti to deregulate its economy and slash its public sector still further. Failure to comply was met with a punishing aid embargo from 2001 to 2004, the death knell to Haiti's public sphere.

This history needs to be confronted now, because it threatens to repeat itself. Haiti's creditors are already using the desperate need for earthquake aid to push for a fivefold increase in garment-sector production, some of the most exploitative jobs in the country. Haitians have no status in these talks, because they are regarded as passive recipients of aid, not full and dignified participants in a process of redress and restitution.

A reckoning with the debts the world owes to Haiti would radically change this poisonous dynamic. This is where the road to repair begins – by recognising the right of Haitians to reparations.

The interview with economist Camille Chalmers was conducted by my partner Avi Lewis for an in-depth report that aired today on Al Jazeera English. The piece, Haiti: The Politics of Rebuilding, offers a deeply compelling portrait of a people who are brimming with ideas about how how to rebuild their country based on principles of sovereignty and equity – far from the passive victims we have seen on so many other networks. It was produced by my former colleague Andréa Schmidt, one of the main researchers on The Shock Doctrine, and is crucial viewing for anyone concerned with avoiding a disaster capitalism redux in Haiti.

A version of this column is published in the Nation (www.thenation.com)