..........................
What people should realize is that oil is plentiful, but the cost of producing it varies greatly. The reason Middle East oil has been exploited first, much to the financial advantage of the Arabs is that it has the lowest cost per barrel produced. With newer technologies, the cost to produce from other sources is coming down, but is still not as low as Middle East oil.
So, more cost effective resources are used first.
Second thing to keep in mind is that there are different types of crude oil. Some, like Venezuelan oil, are heavy and sulfur rich, which means more costs for refining. Middle East oil is called "light sweet crude" for the reason it is easy to refine and has fewer contaminants.
So, the better quality resources are used first.
Therefore, none of this is some scheme on the part of the US to steal anyone's oil.