Re: To colonize or not....
"Preventing" may be too strong a word. Any government that we do a significant amount of business with (like the Saudi's, for example), we support. Support translates into "prop up" pretty smoothly. If a wealthy nation aids a repressive foreign government, it decreases the chances that that government will fall.
Or, going at it from the foreign policy angle, our stated goal in the middle east has, for a long time, been "stability". "Stability" pretty much equals "no revolutions".