CHICAGO (Reuters) - NATO leaders gather in Chicago on Sunday for a summit that will chart a path out of Afghanistan, as Western nations seek to fend off fissures in their alliance and ensure Afghanistan can hold a still-potent Taliban at bay when foreign troops withdraw. President Barack Obama hosts the summit in his home town, Chicago, a day after leaders of major industrialized nations tackled Europe's debt crisis, backing keeping Greece in the euro zone and vowing to take steps necessary to revitalize the world economy. ...
