Why Syria's war, after 400,000 deaths, is only getting worse

WASHINGTON - There is a basic fact about Syria's civil war that never seems to change: It frustrates any attempt at resolution. Despite many offensives, peace conferences and foreign interventions, including this week's Turkish incursion into a border town, the only needle that ever seems to move is the one measuring the suffering of Syrians - which only worsens. Academic research on civil wars, taken together, reveals why. The average such conflict now lasts about a decade, twice as long as Syria's so far. But there are a handful of factors that can make them longer, more violent and harder to stop. Virtually all are present in Syria. Many stem from foreign interventions that were intended...