Some members of Congress are calling for investigations into how America’s 20 year military presence in Afghanistan could come to such a shabby end. Any hearings or investigations should begin – and end — with a thorough analysis of the most recent report of the Special inspector General for Afghanistan Reconstruction (SIGAR).

This report – “What We Need To Learn: Lessons From 20 Years of Afghanistan Reconstruction” – is as close to an autopsy of the U.S. involvement in the country as we are likely to get.

It’s damning reading, a sort of “greatest hits” from the IG’s office recounting the problems involved in nation building. The report also pulls no punches:

While there have been several areas of improvement—most notably in the areas of health care, maternal health, and education—progress has been elusive and the prospects for sustaining this progress are dubious. The U.S. government has been often overwhelmed by the magnitude of rebuilding a country that, at the time of the U.S. invasion, had already seen two decades of Soviet occupation, civil war, and Taliban brutality.

Here’s an excerpt on just how elusive – despite the billions of taxpayer dollars spent – those gains may be:

Effectively rebuilding Afghanistan required a detailed understanding of the country’s social, economic, and political dynamics. However, U.S. officials were consistently operating in the dark, often because of the difficulty of collecting the necessary information. The U.S. government also clumsily forced Western technocratic models onto Afghan economic institutions; trained security forces in advanced weapon systems they could not understand, much less maintain; imposed formal rule of law on a country that addressed 80 to 90 percent of its disputes through informal means; and often struggled to understand or mitigate the cultural and social barriers to supporting women and girls. Without this background knowledge, U.S. officials often empowered powerbrokers who preyed on the population or diverted U.S. assistance away from its intended recipients to enrich and empower themselves and their allies. Lack of knowledge at the local level meant projects intended to mitigate conflict often exacerbated it, and even inadvertently funded insurgents.

There’s much, much more in this report. The sad, and horrifying, part of the story it tells is that every problem identified was made clear in earlier reports. Yet it appears those series of red flags and warnings were ignored.

Again: Congress may feel the need to have hearings to ease its own conscience about what happened and, as usual, to score cheap political points. But unless reports like that from SIGAR are read, understood, and acted on, it is almost guaranteed similar errors, waste, and bloodshed will occur in the future.