For a long time, much of the world saw the eurozone sovereign debt crisis as Europe's problem. Now world leaders, including the United States, realize a eurozone meltdown could have dire consequences for everyone. They are working up a massive rescue plan whose contours are beginning to emerge. Although Britain does not use the euro, that nation's politicians are using their party conventions to issue dire warnings about the euro's fate. And one eminent economist is proposing a novel solution to limit the impact of the European debt crisis.