I read this article with interest. Needless to say, what the Russians are saying seems like mild threats. However, it is nothing of the kind. They just don’t want anyone meddling while they’re supporting their good ol’ buddy Assad.
The Russians are implying that the civil war over there in Syria would escalate if Europe discards its policy of arms embargo. I’d say that they are working to keep Assad in power and maybe get a foot in the door with his successors.
Russians have a history of not realizing what is happening even as they participate in increasing instability. Case in point: The collapse of the Soviet Union. While her satellites were hemorraghing at the the borders, Russians in the USSR proper were acting as if nothing were wrong.