Make no mistake:  the primary purpose of the Sept. 11 attacks was to provoke the US into invading the Middle East.  Osama knew that would be the reaction, and its exactly what he wanted.

Things haven't gone entirely by Osama's script, of course.   For one thing, Osama no doubt assumed he would be dead by now.   For another, Osama most likely expected the US to initiate a lengthy and expensive ground invasion of Afghanistan, rather than the speedy, warlord managed attack that (temporarily) dispatched the Taliban.

Not to worry, though, we went ahead got back in Osama's playbook by invading Iraq.  He wants the US there.  He wants Muslims to see this as a Holy war.  And then he wants the US to get tired of the campaign and retreat, which has been our MO for the last 30 years or so.