The surge of migrants into Europe from war-ravaged and impoverished parts of the Middle East, Afghanistan and Africa has shifted in recent months. Migrants are now pushing by land across the western Balkans, in numbers roughly equal to those entering the Continent through Italy. Much of Europe is reeling from the flow of people seeking safety, jobs and a better life — but who have strained resources, heightened ethnic and religious tensions, and rewired politics in individual nations and throughout the Continent. The new pathway is also causing a sharp rise in anti-immigrant sentiment in the Balkans and neighboring central Europes, bolstering nationalist parties and inspiring protests […]