Civil war starting in 2011 creates a power vacuum in northern Syria that attracts Saddam’s former key strategists, who begin working with ISIS to regain Sunni power. As factions and nations take sides based on their own competing interests, Syria becomes fragmented. ISIS uses the power vacuum to pursue its goal of establishing a totalitarian Islamic caliphate. Chaos and fighting touches off the Syrian migration to Europe that we see today. Here’s a bit more detail.https://youtu.be/j7azThPm8WY