Three Books — And Three Lessons — 20 Years After 9/11

So what have we learned in the 20 years since 9/11?

The Taliban takeover of Afghanistan encapsulated much of the past two decades. A war that began remarkably well for the U.S. had long since turned messy, frustrating and complicated, expanding to include a sprawling mix of goals and aspirations that never really went according to plan.

The global war on terror. The invasion of Iraq. Nation building. Black site prisons and Guantanamo Bay. Drone strikes across the Islamic world. Feuds over domestic surveillance and privacy. The rise of bitter partisan politics in the U.S.

Many books have documented these developments and more are on the way.

Here we point to three very strong new offerings that provide a detailed accounting of events, by Peter Bergen; , by Craig Whitlock; and , by Douglas London.