Syrian Turmoil Threatens ‘Fragile’ Middle East Borders

The civil war tearing Syria apart is threatening to erase century-old borders across the Middle East as what began as a peaceful rebellion against President Bashar al-Assad escalates into a regional religious and ethnic battle.

In Tripoli, Lebanon, Assad’s Sunni Muslim enemies and Shiite supporters, divided by an avenue named “Syria Street,” shelled and shot each other last week, leaving at least 23 people dead. Bloodletting between Iraqi Sunnis and Shiites has reached its most sustained level since the 2011 U.S. troop withdrawal, killing almost 300 people last week. In northeastern Syria, Turkish Kurds are battling Sunni Arabs.