America must use sanctions cautiously

WHAT is America’s greatest source of power? Its military might is unparalleled. Its market is vast. Alongside these assets stands the dollar. The world depends on America’s currency, and hence on access to dollar payments systems and the banks America has effective control over. Greenbacks fuel trade everywhere. On average, countries’ dollar imports are worth five times what they buy from America. More than half of all global cross-border debt is dollar-denominated. Dollars make up nearly two-thirds of central-bank reserves. That gives the Treasury a veto over much of global commerce.