UK formally serves notice that it’s quitting the European Union. Beyond a doubt, this decision was a grave mistake — but it’s done, and now Britain and its European partners need to arrange the friendliest possible divorce. The EU’s initial posture has been anything but friendly, which is understandable. Britain is the defaulting party and shouldn’t expect gratitude. Europe’s …

  Middle East is a seething cauldron. Although US President Donald Trump called the fight against IS his top priority and vowed to wipe IS from the face of earth, the young administration is wary of getting mired in the region. Trump criticized past presidents for getting deep in Iraq and other conflicts. Trump does not want to go solo …

  Taxi companies that compete with Uber and media companies that are up against Facebook know it: In a rivalry between regulated and unregulated firms, the latter have an unfair advantage. It also applies to banks, which spent the past ten years losing market share to companies that regulators ignored. In a fresh working paper, Greg Buchak and Gregor Matvos …