It's nothing we didn't know already, but an inspector general's report on Afghanistan reconstruction has found that after 15 years and $5 billion, the effort has largely failed.

NBCNews:

The Special Inspector General for Afghanistan Reconstruction (SIGAR) says the U.S. set unrealistic expectations for stabilizing Afghanistan on a short timeline, that the Obama administration lacked the political will to invest the necessary time and effort to stabilize the country, and that some efforts to bolster the Afghan government actually backfired.

"[Our] overall assessment is that despite some heroic efforts to stabilize insecure and contested areas in Afghanistan between 2002 and 2017, the program mostly failed," said John Sopko, head of SIGAR, at a Thursday morning event announcing the report.

The report examines stabilization efforts from 2002, soon after the U.S. began military operations in the country, to 2017.

In 2003, the U.S. launched a counterinsurgency mission in Afghanistan that would come to include a clear-hold-build strategy.  U.S. forces were instructed to clear an area, hold it and then build institutions.

The report says the effort proved ineffective in stabilization because the military focused on the most dangerous districts first, where poor security made it hard to move on to the building phase.  U.S. civilian agencies were compelled to conduct their stabilization programs in dangerous areas not ready for rebuilding, and once coalition troops and civilians left those districts the stabilization ended.

Some efforts to introduce increased Afghan government control also produced unintended consequences, according to the report, because they created more opportunities for corruption.

By 2008, the security situation in much of the country had deteriorated and insurgent attacks began to mount.

Despite herculean efforts to train the Afghan army and police, the security situation is worse today than it has ever been.  The Afghan government controls very little territory, with the Taliban and corrupt warlords ruling the rest. 

Certainly, there have been some local successes.  But overall, the situation is grim.  As of last October, 56% of Afghan territory was either under direct control or under the influence of the Taliban.  Whole provinces have succumbed.  Efforts to negotiate with the Taliban have so far been futile.

Trump is not going to send 50,000 troops back to Afghanistan in order to stabilize the country.  And while some units are performing well, the Afghan army as a whole is just not up to the challenge to local security posed by the Taliban. 

Should we face facts and withdraw the remaining troops, reduce U.S. aid, and abandon the Afghan government to the Taliban?  It's something that certainly should be considered.