Watch how the Syrian civil war became the mess it is today.
After four-plus years of fighting, Syria's war has killed at least 250,000 people and displaced 12 million people. And, though it started as a civil war, it's become much more than that. It's a proxy war that has divided much of the Middle East, and has drawn in both Russia and the United States. To understand how Syria got to this place, it helps to start at the beginning and watch it unfold.