Russia warns the US and its allies it will shoot down any aircraft flying west of the Euphrates river.
It's a new red line and this time in the form of a river.
Russia says it will shoot down any aircraft that flies west of the Euphrates river in Syria.
The US military shot down a Syrian fighter jet on Saturday. The White House is insisting the action was taken in self defence.
But the Russian and Syrian governments have condemned it.
So what does this mean for the war in Syria?
Presenter: Sohail Rahman
Pavel Felgenhauer - Defence and Military Analyst and a Columnist with the Russian newspaper Novaya Gazeta.
Jean-Marc Rickli - Head of Global Risk and the Geneva Centre for Security Policy.
Larry Korb - Senior Fellow at the Center for American Progress and a former naval Flight Officer.
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