All by design, Comrade. All. By. Design. *SPIT*
Obama made a paper Afghan security forces and it was only half as big as they said and the commanders got to keep half the money
“....Afghan security forces collapsed so quickly and completely...”
I understand the Afghan forces were being paid by the US until recently when the Afghan government took on that responsibility. They paid the soldiers very late and sometimes not al all. They were not receiving military supplies and morale among the troops was extremely low. They were also disgusted with the corruption in government. Many had left their posts and gone home.
It is said that at each target city, the Taliban commander called for a meeting with the Afghan military leader and offered a very large sum of money to walk away. And that is what they did.
Taliban is an extremely wealthy organization. They have a bigtime drug operation, ransoms, and donations from Islamic countries in support.