Why the US military won’t stop Russian and Syrian forces from violating a cease-fire
By: Kyle Rempfer  
Syrian regime forces, buoyed by Russian air power, have pushed into rebel territory in the Syrian city of Deraa, violating the de-escalation zone agreement negotiated between the United States, Russia and Jordan last year.
However, the U.S. military will not be stepping in to enforce the failing cease-fire.
While the U.S. State Department expressed concern over the offensive, a message to locals from the U.S. Embassy in Amman, Jordan, has made it clear that American forces have no intention of stepping into the fray.
https://www.militarytimes.com/flashpoints/2018/06/27/why-the-us-military-wont-stop-russian-and-syrian-forces-from-violating-a-cease-fire/