Why did the Afghan army disintegrate so quickly?

The billions spent by the US and NATO on the Afghan military could not fix major internal flaws.

On August 15, the Taliban captured the Afghan capital Kabul and declared the war in Afghanistan over. The lightning speed with which the group made major territorial gains as the Afghan National Defence Security Forces (ANDSF) retreated without putting up a fight shocked many. Over the last 20 years, the US spent more than $83bn training, equipping and developing the Afghan national army, police, air force, and special forces. Yet, under the advance of an armed group carrying light weapons, the ANDSF fell apart in a spectacular fashion. The unprecedented pace of the Taliban’s territorial gains surprised even US intelligence, which had projected that it would take months for the group to establish control over the country. As a result, the US and several other Western countries have had to redeploy thousands of troops to help with the emergency evacuation of their citizens and diplomatic staff from Kabul.