I think the shale revolution probably changed the calculus. It removed the "dependency on foreign oil" argument from the debate completely in the U.S. (though

I think the shale revolution probably changed the calculus. It removed the "dependency on foreign oil" argument from the debate completely in the U.S. (though you still hear it mentioned from time to time without merit). It also reduced the cost of energy in the U.S. which eliminated a lot of the economic pressure.