Well, my take on 9/11 -- based on known factors such as the kid in Texas who told his teacher that "WWIII will start tomorrow, it will start in the US, and the US will lose," and the fact that after the FAA ordered the entire civil airline transportation system grounded, there were about a dozen other flights with box-cutter-boys on board -- is that he planned on bringing the US to its knees on 9/11. Where he intended to go from there I have no way of knowing. Perhaps he planned on delivering a coup de gras in the form of a series of mini-nukes to the survivors, perhaps not.
I think however that it's been fairly well established that his intentions for 9/11 went far beyond that which he actually accomplished that day.