Syria's civil war, four-plus years after it began with protests and crackdowns in 2011, has grown into an international proxy conflict. It includes regional powers Iran and Saudi Arabia as well as global powers such as the US and Russia. There are foreign militias, Syrian militias, and Kurdish militias. There are crisscrossing alliances and rivalries. Even the countries and groups ostensibly on the same side often have very different goals and strategies.
To help you follow what's going on, who's involved, and what each side is trying to do, we've charted out the most important actors and their relationships. Click on the logos to see the web of relationships, or click on the line between any two actors to see how they interact.
One thing you'll notice: For all the complications and contradictions, the conflict at the center of it all, the one dynamic around which so much of the war organizes, is still the battle between Syrian leader Bashar al-Assad and the Syrian rebels.