What We Need to Learn: Lessons from Twenty Years of Afghanistan Reconstruction is the 11th lessons learned report issued by the Special Inspector General for Afghanistan Reconstruction. The report examines the past two decades of the U.S. reconstruction effort in Afghanistan. It details how the U.S. government struggled to develop a coherent strategy, understand how long the reconstruction mission would take, ensure its projects were sustainable, staff the mission with trained professionals, account for the challenges posed by insecurity, tailor efforts to the Afghan context, and understand the impact of programs. There have been bright spots—such as lower child mortality rates, increases in per capita GDP, and increased literacy rates. But after spending 20 years and $145 billion trying to rebuild Afghanistan, the U.S. government has many lessons it needs to learn. Implementing these critical lessons will save lives and prevent waste, fraud, and abuse in Afghanistan, and in future reconstruction missions elsewhere around the world.