It's about global oil supply.
Here’s the correct answer:
America’s vital interest in the Middle East can be summed up in three words: oil, oil and oil. That’s it. If that region wasn’t sitting on such huge reserves, America wouldn’t give it a second thought, with the exception of its security guarantee to Israel.
It may be comforting to pretend that our enemies "hate our freedoms," as President Bush stated, but it is a mistake to ignore the truth.
President Bush is not the first to ask: "Why do they hate us?" In a staff discussion 44 years ago, President Eisenhower asked his National Security Council about "the campaign of hatred against us [in the Arab world], not by the governments but by the people".
His National Security Council outlined the basic reasons: the US supports corrupt and oppressive governments and is "opposing political or economic progress" because of its interest in controlling the oil resources of the region.