Osama in particular seemed to like the idea of the US supporting, but not being direcly involved with troops in the Middle East. After the Russians left Afganistan, the US withdrew their support and it created that good old tribal warlord thingy.
What seems to have driven Osama around the bend is that the US rebuffed his offer to take care of Saddam with his happy bandits. Instead, the US set up a large base of operation in Saudi Araibia and in Osamas mind, desecrated a holy land. Yes, we know Osama is a very very bad man
, but doesn't he really just want the US out of the Middle East? I mean, where was this threat of terrorism when the US wasn't involved with ground forces?