Wars rarely have a single cause. Anyone who thinks that war was actually fought over Iraqi oil probably still believes in the Easter Bunny and the Tooth Fairy too. While it was certainly a contributing factor, the US was neither dependent upon nor really a significant purchaser of Iraqi oil before or after the invasion.

Was it about WMDs? Who really knows? While the vast preponderance of the intelligence available at the time certainly indicated that there were none, did Bush II believe it? The idea that they existed but were somehow moved at the last minute to Syria or Libya is as much a fairy tale as the stories of squadrons of new Soviet-era fighters cocooned and buried in the desert. It is most likely that the major cause for Gulf War part I and part II was the very real non-nuclear military threat that Iraq posed to Saudi Arabia.