I believe the answer is: Israel
There were several train of thoughts that commonly held to explain us support toward israel, i would give two of them.
The first one is that the soviet union had a really huge influence on middle eastern countries. Since at that time soviet union was involved in the cold war with united states, US decided to choose the opposition.
The second one is that supporting israel would provide US with the chance to obtain huge chunk of areas with huge amount of oil resources which previously belong to the middle eastern.
