AP Photo

About a year ago, I joined a small group of journalists in Beirut for a meeting with Fouad Siniora, then the prime minister of Lebanon. Siniora had held the position since the middle of 2005, when Syria ended its almost three-decade-long military occupation of its much smaller neighbor following the assassination of former Lebanese Prime Minister Rafiq Hariri—a crime many assume was perpetrated either by Damascus or its allies in the Shiite terrorist group Hezbollah. At the time, the withdrawal was seen as a possible paradigm-changing victory for Lebanon. But if the Lebanese believed that the end of nearly thirty years of subjugation to the Syrian military and intelligence apparatus would put an end to the violent instability that has...