Just when you thought Syria's long-running civil war couldn't get any more complicated -- it did.
On Wednesday, President Trump tweeted a message taunting Russia and telegraphing military action in Syria after a suspected chemical attack in the war-torn country.
The war may have started out as an uprising against President Bashar al-Assad, but now it's a free-for-all.
ISIS has lost control of most of its territory after it came under attack from all sides.
But victories over ISIS mean that the other combatants are now freer to attack each other.
Turkey opened a new front against Kurds in northern Syria in January.
The Kurds -- including the YPG -- had been among the most effective fighters against ISIS. Rebel groups, such as the Free Syrian Army, are fighting the regime. And there are also competing Islamist groups like Jabhat Fateh al Sham.
And that's just the half of it.
Russia supports Assad and is fighting ISIS. The US is also fighting ISIS, but not to support Assad -- it has bombed Syrian military targets in retaliation for a chemical attack on civilians.
The US is backing the YPG, and Washington and Ankara are NATO allies. (Turkey has let the US bomb ISIS from one of its bases.) But Turkey sees the YPG as a terrorist group indistinguishable from the Kurdish separatists on Turkish soil.
Iran, and the Iranian-supported Hezbollah militia, are backing Assad.
And the outbreak of fighting between the Turks and the Kurds just might give ISIS enough breathing room to regroup.
Confused? That's why we figured it'd be easier if we just drew you a picture.