It’s often said that history doesn’t repeat itself, but it often rhymes. If only humanity could stop repeating the worst parts of our historic verse. Politicians, again at the center of this week’s follies, have found a way to make old mistakes sound new: announce them at a press conference. This week’s stories come from both sides of the Atlantic, and each promises relief from real problems. Each also assumes supply will politely ignore what politicians tell it to do. First, in the U.S., is Republican lawmakers’ suggestion to ban diesel and possibly broader oil and fossil fuel exports. The plan has more holes than the Detroit Lions’ defense and fails to acknowledge the realities of fuel production and di...