The war that ended the bloody breakup of Yugoslavia -- Europe’s worst conflict since World War II -- remains unresolved, with its adversaries still locked in a territorial dispute. More than two decades after they stopped fighting, Kosovo is demanding recognition as an independent state, while Serbia refuses to let it go. The disagreement has thwarted their progress toward European Union membership and opened space for a geopolitical tussle, where the U.S., Russia and China are grappling for inf