Is Alan Greenspan right? Did we invade Iraq just for the oil?

I think it's obvious. After all, within 5 HOURS after the 9/11 attacks, Rumsfeld ordered his staff to gather as much "evidence" as possible linking the attacks to Iraq. Obviously, Bush & Co. wanted to go to Iraq all along and they saw the attacks as their golden opportunity to do so. Plus, if they really gave a damn about getting justice for the 3,000 who died in the attacks or about making the US safer, they would have focused on capturing bin Laden rather than invading a country that was in no way involved in the attacks. I think that the reason for the attacks is obvious. Simply put, it was oil and the desire of businesses like Halliburton to make a profit.