@msolga,
You are very correct. Naturally, we had to go into Afghanistan to attack al-Qaida, which we quickly defeated. (Unfortunately, the Bush administration allowed bin-Laden and the other leadership to escape the country.) We should have then quickly left the country.
Instead, Bush, who thought we were omnipotent, occupied the country, leading to the present mess we are in.
We should now leave the country and let the Afghans run their own affairs.