In the old telling, corruption blighted seedy postcolonial states and prevented them from moving up the development ladder. They scored badly in corruption metrics. Successful states, in contrast, performed impeccably in corruption rankings: they had strong institutions, functioning markets and clean politics. Over the last decade, this fraudulent if comforting narrative has had to be jettisoned under the weight of various court cases, investigative efforts and data leaks such as the release of the Panama Papers. Corruption is now understood to be global, linking poor and rich countries through the international financial system.

The oil sector is hardly the only culprit, but it encapsulates this reality to perfection. In Crude Intentions, Alexandra Gillies focuses on the period from about 2004 to 2014, when the price of oil rose to historically high levels, to weave a compelling tale about how unprecedented amounts of money from oil-rich states were siphoned off and where they ended up. Her cast of characters includes multinational oil companies and the elites of resource-rich states in Africa and Asia as well as national oil companies, oil traders and oil service firms. It also encompasses the mostly Western enablers – wealth managers, accountants, bankers, real estate dealers, management consultants, auditors – who played an indispensable role. Gillies, a researcher and activist with fifteen years of work in the field behind her, is well positioned to tell this story. Aspects of it are unavoidably technical, but the book’s accessible style makes them easy to comprehend.

While Crude Intentions contains forays into Brazil, Angola, Malaysia and Central Asia, among other places, the sections on the oil industry in Nigeria, on which Gillies is an expert, are the most insightful. While living in Nigeria in 2008, she saw signs of reform in the country’s oil sector, but as prices rose she witnessed a degree of plunder shocking even by Nigerian standards. Corruption escalated under the new president, Goodluck Jonathan, and his cronies squeezed out billions for themselves through crooked yet, according to Nigerian law, sometimes legal means. The election in 2015 of a ‘less corrupt president’ and, especially, the drop in oil prices brought the worst thieving to a halt. For Gillies, this reversal shows that quasi-democracies with free presses and working institutions can, however awkwardly, unwind some corrupt practices. She argues likewise with regard to Brazil, where arrangements involving former president Lula da Silva’s Workers’ Party, construction giants such as Odebrecht and state-owned enterprises such as Petrobras imploded as a result of the criminal investigation known as Operation Car Wash. It is debatable whether these were consequences of genuine reform or merely of rival elite groups jostling for power, but there is no doubt that heads have rolled.

Countries with stable authoritarian governments, such as Angola and Azerbaijan (not to mention the Persian Gulf states), are much more difficult to reform from within. Such governments tend to run their oil industry efficiently enough to maximise gains for insiders, while having the means to repress populations and stay in power for the long haul. In these situations, effective efforts to stem corruption can often only come from without. However, as Gillies shows, the international environment is in many ways a force multiplier for these regimes.

This is because corrupt regimes, democratic or authoritarian, have one thing in common: the networks of corruption they rely on. These are thoroughly globalised. Gillies is not the first author to show this – the work of Nicholas Shaxson, Tom Burgis and Oliver Bullough comes to mind – but her detailed presentation of the evidence serves as a stinging indictment. Leading financial centres such as New York, Zurich, London and Paris (all of greater consequence than tropical tax havens) enable illicit capital flows. Cases such as the laundering of $230 billion by Danske Bank (Denmark’s largest bank) through its Estonian branch reveal that well-regulated economies are an integral part of this system. Malaysia’s 1MDB, a development fund that allowed the misappropriation of an estimated $4.5 billion, was intricately connected to actors ranging from Goldman Sachs to Coutts. Throughout Crude Intentions, enablers are seen repeatedly helping corrupt elites to extract resources, launder the proceeds and, finally, reposition themselves as respectable metropolitan socialites. Most seek permanent membership of the global 0.1 per cent. They often attain it. This does not simply soil the politics of oil-rich countries. Dirty oil money is used to co-opt Western elites. It makes its way into sports clubs, universities, think-tanks and arts institutions (and political parties too) in a tidal wave that, in the words of the book’s subtitle, ‘contaminates the world’.

There is some hope. ‘Every time a corruption scheme reaches across borders’, she argues, ‘it exposes itself to actions by foreign anticorruption actors.’ Some law enforcement agencies and tenacious organisations, such as the International Consortium of Investigative Journalists and Global Witness, have unearthed authoritative evidence of malfeasance. The US Kleptocracy Asset Recovery Initiative and the UK’s Unexplained Wealth Orders may provide promising tools for fighting international corruption.

Yet it is much too soon to be sanguine about this. The Western countries claiming to lead the fight against corruption are its beneficiaries and therefore at best ambivalent about a real clean-up. Improvements, such as they are, happen slowly enough for those handling the corrupt money to provide their oligarchic clients with smart solutions. There is no global consensus on ending illicit financial flows. China, Saudi Arabia, Russia and other powerful autocracies are understandably keen on the status quo. Even as some financial centres in Europe and North America get more tightly regulated, Asian ones such as Dubai provide alternative shelters for dirty money.

Gillies sees a dawning international effort. This may come across as optimistic, but those fighting against corruption must believe in their ultimate success in order to persevere. I can scarcely think of a more necessary endeavour for the development of poor countries and the maintenance of decent politics in richer ones.