On August 9, 2007, the French bank BNP Paribas—one of the largest banks in Europe—announced that it was freezing $2.2 billion worth of its investment funds as a result of problems in the U.S. subprime mortgage sector. It was “the first indication that the downturn in housing prices, which had begun in early 2007, would have global ramifications”—in other words, “what most experts consider to be the true start of the global financial crisis,” wrote Adam Tooze in a 2018 essay. This weekend, just over 17 years later, we’re featuring Tooze’s piece on the U.S. Federal Reserve’s secret efforts to save the world’s financial system—and how they transformed the global economy.

In the aftermath of the crisis, European leaders were “content to blame everything on the Americans,” Tooze asserted. But bankers on both sides of the Atlantic “created the system that imploded in 2008,” and the collapse “could easily have devastated both the U.S. and the European economies had it not been for improvisation on the part of U.S. officials at the Federal Reserve,” including by devising rescue mechanisms for foreign banks, wrote Tooze. The Fed’s overseas interventions amounted to a fundamental transformation of the global financial system—one in which the dollar remained the world’s preferred commercial currency and the Fed emerged as the “global lender of last resort.”

The full details of these arrangements, though, were not disclosed until years later, in 2011. “There was good reason for secrecy,” Tooze argues: “announcing that the world’s most important central banks were desperate for dollar funding could have frightened international markets.” The result, however, “is that the Fed’s actions to save the global financial system have largely been forgotten.” And, as Tooze wrote in 2018, “it is an open question whether it will be able to repeat its efforts on a truly global scale when the next crisis arrives.”