When John D Rockefeller wanted to punish a rival, he cut prices to force them to operate at a loss. The father of the modern oil industry had a name for it: a “good sweating.” A century later, OPEC+ is giving Big Oil the modern equivalent of Rockefeller’s time-tested tactics. Not everyone will be fit enough for it. For the last two-and-a-half years, Big Oil has enjoyed a bonanza.