"'We do not get that large a percentage of our oil from the Middle East... And one of the reasons that we are sort of assuming this role of policeman of the Middle East has more to do with making Japan and some other countries feel that their oil flow
is assured... so that they don't then feel more need to create a great power, armed forces, and security doctrine, and you don't start getting a lot of great powers with conflicting interests sending their militaries all over the world.'"

This perspective offers a rational explanation for things like "North Korea" that have had me scratching my head. I'd like to see a counter point, but I think this might be somewhat close to the truth.

"'We do not get that large a percentage of our oil from the Middle East... And one of the reasons that we are sort of assuming this role of policeman of the Middle East has more to do with making Japan and some other countries feel that their oil flow
is assured... so that they don't then feel more need to create a great power, armed forces, and security doctrine, and you don't start getting a lot of great powers with conflicting interests sending their militaries all over the world.'"

Originally recommended by Decius this is an interesting article, but there are a few flaws. It's claimed that only 25% of U.S. oil comes from the Gulf, but it is poorly assumed that that is insignificant, which is not true. Also, what is missed is that large parts of the Middle East (Egypt, Saudi Arabia, Kuwait) are effectively U.S. supported governments and the ability to influence them and their oil allows the U.S. significant influence with these same countries that have dependence. So, I basically agree, but I think that there is a certain viewpoint that has been ignored.