Saudi Arabia
We support their retrograde dictatorship.
We did the same with Iraq, until Saddam got too big for his boots.
We did the same with Iran, until the Shah became so autocratic that he paved the way for the Ayatollah.
We buy oil from client states. You have it right when you say we were a major exporter. We aren't anymore. So we seek to secure oil-producing areas so they will be more compliant.
Notice how we tend to get involved in the affairs of nations who have something we want. Nations who don't have anything we want can go hang, until people like Nicholas Kristol holler enough to make us ashamed.