Does Bush really Want Liberation Or OIL?

It would be stupid to think that bush is in Iraq soley on the purpose of liberating the Iraqi people. I mean think about it, the united states uses up more gas than any other nation on the world. The American people of America have made oil a mandatory need of life. So then a question comes up, out of all the nations that are at war with themselves and each other, why pick a nation that has one of the worlds largest oil supply?