Already gone! Russia defaulted on its foreign-currency sovereign debt for the first time in a century, the culmination of ever-tougher Western sanctions that shut down payment routes to overseas creditors. For months, the country found paths around the penalties imposed after the Kremlin’s invasion of Ukraine. But at the end of the day on Sunday, the grace period on about $100 million of snared interest payments due May 27 expired, a deadline considered an event of default if missed. It’s a grim marker in the country’s rapid transformation into an economic, financial and political outcast. The nation’s eurobonds have traded...