| French historian Fernand Braudel identified three cycles of history. The shortest is the day-to-day flow of events; Braudel called them “fireflies” on the stage. Next up are paradigm shifts — like the end of the Cold War — that can play out over decades or longer. Finally, there’s the longue durée: the bedrock of climate and geography that shapes everything else and changes only over centuries or millennia. Six months into US President Donald Trump’s second term, it’s clear that the course of events has changed. What’s the collective noun for a group of fireflies? Probably not “paradigm shift,” but in this case that’s what it adds up to. The US pivot from free trade and global security to a sharper focus on the national interest has the makings of a decades-defining transformation, reversing the global integration supercharged by the end of the Cold War. In the decades after World War II, the US was the champion of free trade, the anchor for global security and the gold standard on governance. Now, it has raised tariffs to the highest level since the 1930s, told allies they need to pay for protection and crossed red lines on independence for the Fed and statistical agencies. That’s a major break, and an important moment for the global economy, shifting patterns of growth and inflation, borrowing and debt. The geopolitical landscape has shifted just as decisively. Jolting though it is, Trump’s focus on America First is a reflection of a new reality where the US is no longer the world’s sole superpower. Regardless of who occupies the White House next, US allies and adversaries will continue to reorient around that new state of affairs. How about Braudel’s longue durée — the slowest moving cycle of history on which everything else rests? Could even that be at an inflection point? Maybe. Trump has pulled the US out of the Paris climate agreement, again. The global fight against climate change will continue, but without the world’s second-largest emitter, it gets harder. The arrival of artificial general intelligence could also prove an epochal shift. “History,” Braudel wrote, “may be divided into three movements: what moves rapidly, what moves slowly and what appears not to move at all.” Right now, events are moving almost too fast to track and the slow-moving Pax Americana is heading rapidly toward the dustbin of history. If global temperatures rise much further or machines start thinking for themselves, there will be movement even in the cycle that appears not to move at all. — Tom Orlik is the chief economist for Bloomberg Economics and Jennifer Welch is the chief geoeconomics analyst. | 
