The financial crisis among the 17 nations that use the euro has been characterized by a series of missteps and missed opportunities on the part of the region’s political leaders, whose preference for cautious incrementalism has allowed a seemingly limited set of problems in Greece to threaten the entire currency union. They are scheduled to meet later this week for the latest Brussels summit, and they promise that the outcome this time will be different — a convincing set of proposed treaty changes and other measures that will fix the euro’s underlying problems and stabilize financial markets. We’ve been here before . . . Read related article.