This isn't really accurate. The Northern Alliance entered into an agreement with the US to secure the country. An insurgency sprang up and we fought it for 20 years before giving up. Since this is now after the fact, we can safely say the Taliban ran the insurgency the whole time.

The Taliban are a military and political group compromised of an ethnic minority in Afghanistan. It's not even that the US lost to "goat herders with guns". We failed to secure a small country against a well organized, armed minority.