America commemorates two grim anniversaries this month: 9/11 and 9/15. Almost a decade has passed since hijacked aircraft flew into the twin towers, killing nearly 3,000 people and transforming America’s relations with the world. Two years have elapsed since the collapse of Lehman Brothers triggered a global financial crisis and provoked fears of a new Great Depression.

The two events took place within a few miles of each other in Manhattan. Each of them changed the world profoundly. But when the history books are written, which will seem more important?

My guess is that it will be the financial crisis that ends up looming larger. That might seem a strange judgment. To many Americans, 9/11 definitively marked the end of an era. A decade of Gatsbyesque good times between the collapse of the Soviet Union and the attack on the US had come to a horrific end. Two wars, in Afghanistan and Iraq, flowed directly from 9/11. The US launched into a struggle with militant Islamism and a “war on terror” that continue to this day.