It's about access to and control of oil. It was also about a former key employee of the $ySSTem (Saddam Hussein) who became disobedient. He tried to go into business for himself. Such disobedience is not tolerated by either the Mafia OR the Coporatocracy. The disobedient and defiant are crushed ruthlessly.

Further to that it's about securing bases in the center of the Middle East which provide good staging points for hypothetical future attacks on other defiant or disobedient people...such as the Iranians, the Syrians, and possibly the Saudis (at some point, if things change).

None of this has anything to do with protecting Americans, but it does have something to do with protecting their overseas oil sources.

If the USA wasn't so tied down right now in the Middle East, you'd see some very peculiar things happening in regards to Venezuela right now too. Again, because Chavez is steering an independent course. He is disobedient and defiant towards to Coporatocracy. That usually leads to an early and violent death for popular leaders in Latin America. Almost always, in fact.