On Aug. 16, 2021, the Special Inspector General for Afghanistan Reconstruction released a report: “What We Need to Learn: Lessons from Twenty Years of Afghanistan Reconstruction.”

The report was overtaken by the news, as only the day before the Afghan government had collapsed and the Taliban rapidly seized power.

But one year later, it is a document — based on 13 years of work, mountains of data and more than 760 interviews — worth studying carefully.