The huge variable being ignored here: the sustained high price of oil along with technological breakthroughs has made extraction of oil shale economical. The U.S. has the largest reserves of oil shale in the world, over twice the total recoverable oil reserves of Saudi Arabia. My sister is a petroleum geologist: a large proportion of oil production has moved back domestically over the last 5 years.

Most recent geopolitical shifts can be traced back to the Middle East no longer being strategically important to U.S. interests any more. In 2007 we were worried that rising oil prices would trigger a financial crisis that would severely hurt American interests; controlling mid-east oil was critically important. By 2010 the financial crisis had happened, it was clear that gas prices were not coming down, and oil production was moving back domestically. There was no longer any reason for us to be in Iraq, so Obama got us out, and as far as the U.S. is concerned the Middle East can collapse into the Dark Ages and we won't care, as long as they leave Israel alone. So far ISIS has been more anti-Palestine than anti-Israel.