I used to think conspiracy theories were the refuge of the powerless and the uneducated. The conviction that dark and secretive forces are manipulating world events was the mark of an outsider, surfing the internet or shouting in the streets. In the corridors of power they knew better. As British civil servants like to murmur, when things go wrong, it’s usually “a cock-up, not a conspiracy.”

But conspiracy theorists have moved from the streets to the suites. They have become presidents of countries, including Turkey and Brazil. In the US, Donald Trump — who sees plots against him everywhere — is planning his political comeback. The most dangerous conspiracy theorist of them all is Vladimir Putin, who is currently threatening the world with nuclear war.

His speech last week, announcing the illegal annexation of parts of Ukraine, was stuffed full of conspiratorial thinking. According to Putin, the collective west doesn’t “want us to be free; they want us to be a colony . . . They want to steal from us.” On previous occasions, Putin and his key advisers have made reference to the conspiracy theory of the “golden billion.” This holds that the west has decided that the world only has enough resources to support a billion people — and that therefore it intends to break up Russia and steal its resources. Last week he claimed that western countries have abandoned religion and embraced “satanism.”

It is increasingly evident that Putin actually believes many of the conspiracy theories he peddles. A deeply conspiratorial view of the world has driven his actions for years. He has repeatedly insisted that “colour revolutions” in Ukraine and Georgia were not spontaneous democratic movements, but “coups” manufactured by western intelligence agencies.

Putin is uniquely dangerous. But he is not the only president who is also a conspiracy theorist. As he faces the possibility of electoral defeat, Brazil’s leader, Jair Bolsonaro, is promoting the idea of a vast leftist conspiracy to steal the election from him. He has also embraced the unproven theory that the COVID-19 virus was manufactured in a laboratory.

Giorgia Meloni, who is expected to be Italy’s next prime minister, is fond of conspiracy theories. She has flirted with the “great replacement” theory — which holds that there is a plan, hatched by elite financiers, to dilute Europe’s Christian culture by promoting immigration. The end goal, apparently, is to turn Europeans into “slaves” and mindless consumers, stripped of their national and gender identities.

With dreary predictability, Meloni — like Trump and Viktor Orbán in Hungary — has suggested that the key figure working against her country is the 92-year-old Jewish financier and philanthropist, George Soros. “When you are a slave, you act in Soros’s interests,” she has declared.

Another powerful leader who rails against Soros is Recep Tayyip Erdoğan. The president of Turkey often blames his country’s economic problems not on his own ineptitude, but on a mysterious “interest rate lobby” that supposedly wants to impose usurious interest rates on ordinary people.

Trump’s rise shattered any illusion that the well-established democracies of the west were immune to this sort of thing. The former, and perhaps future, president launched his political career by promoting the “birther” lie — which held that Barack Obama was not born in the US. He has been a prolific promoter of conspiracy theories ever since. This culminated in his insistence that the 2020 presidential election was stolen from him.

Conspiracy theories have existed for centuries, since the age of witch-burning and before. But in our era of globalisation they are particularly favoured by extreme nationalists, who see shadowy foreign forces lurking behind every setback or national humiliation.

A retreat into such theories involves a flight from reality, which then invites further disasters. As things go wrong, the natural reaction for a conspiracy theorist is to double down, claiming that the disaster their policies have produced is further evidence of the original conspiracy.

The pressure of events can make even normally rational policymakers reach for the comfort blanket of conspiracy theories. At the height of the euro crisis, I encountered EU policymakers who were flirting with the idea that it was all caused by hedge funds, in league with the Financial Times. Now that it is Britain’s turn to go through the financial wringer, some rightwing commentators in the UK suspect a foreign conspiracy to derail Brexit.

Those leaders who were already inclined to conspiratorial thinking tend to become even more paranoid, as things go wrong. (In the immortal words of Kenneth Williams in Carry on Cleo, “Infamy, infamy, they’ve all got it in for me.”) Putin’s annexation speech last week was a classic example. Everything that has gone wrong for Russia, since his decision to invade Ukraine, was cited as further evidence of the fiendish western conspiracy that “justified” the invasion in the first place.

Some years ago, Angela Merkel, the former German chancellor, suggested that Putin had lost touch with reality and was living “in another world.” That world is one in which hidden enemies and plots abound. It is the world of conspiracy theories. Tragically, Putin’s diseased imagination has unleashed a needless, brutal and increasingly dangerous war.

Gideon Rachman became chief foreign affairs columnist for the Financial Times in July 2006. He joined the FT after a 15-year career at The Economist, which included spells as a foreign correspondent in Brussels, Washington and Bangkok. He also edited The Economist’s business and Asia sections. His particular interests include American foreign policy, the European Union and globalisation.

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