A line has been drawn on the Syrian conflict – and Russia has made it clear where it stands.
By sending S-300 anti-aircraft missiles to Damascus, the government of Vladimir Putin is expecting an attempt by three members with a permanent seat on the UN Security Council to unilaterally set up no-fly zones over Syria.
It is calculating that with Hezbollah openly committed to achieving victory for the regime of Bashar al-Asad, and thus with the potential of dragging Lebanon into this conflict, a further escalation by the US, UK and France could trigger a full-scale regional war involving Iran and Israel.
Some commentators are arguing that this is already the case.
If that is so, it is currently at a relatively low-level – compared that is to what an all-out war could mean for the region and beyond.