As we mark the decennial of the collapse of Lehman Brothers, there are still ongoing debates about the causes and consequences of the financial crisis, and whether the lessons needed to prepare for the next one have been absorbed. But looking ahead, the more relevant question is what actually will trigger the next global recession and crisis, and when.

The current global expansion will likely continue into next year, given that the US is running large fiscal deficits, China is pursuing loose fiscal and credit policies, and...