There are 30,000 US citizens living in foreigner compounds, and working in Saudi Arabia. There are also thousands upon thousands, of additional quest workers, from around the globe. You don't think those barbarians, could run all the modern equipment they purchased, do you?
Which is precisely why we're having a problem today. We made the cretins rich by discovering oil in their country, and using our technology to get it out of the ground. Their "thanks" was to break all agreements, nationalize, (or steal) it, and tell us to get the hell out.
We got out alright, but we forgot to do one thing. We should have bombed all of the wells and refineries. They'd still be scratching their heads today, while looking at that black, sticky stuff. Another weak response on the part of America that created a monster.