We actually know their motivations because Bin Laden didn't hide his agenda. He wrote a fair bit on the topic. He wanted to force a change in US foreign policy to stop supporting Israel specifically and to leave the middle east in general. He saw himself as an Islamic anti-imperialist. It was actually pretty straight forward.
step 1: have big terrorist attack on American civilians
step 2: American civilians ask "why me?", his words not mine btw.
step 3: civilians find out what US gov has been doing in the middle east and call for change.
In hindsight its an incredibly naïve plan. And I think it ironically shows a lack of knowing your enemy on his part. Americans don't take well to being attacked or intimidated. If you want them to leave you alone the worst thing you can do is provoke them to action.
step 1: have big terrorist attack on American civilians
step 2: American civilians ask "why me?", his words not mine btw.
step 3: civilians find out what US gov has been doing in the middle east and call for change.
In hindsight its an incredibly naïve plan. And I think it ironically shows a lack of knowing your enemy on his part. Americans don't take well to being attacked or intimidated. If you want them to leave you alone the worst thing you can do is provoke them to action.