Turkey, which has long sought Syrian President Bashar Assad's transition out of power, has been supporting some of the most powerful rebel groups in northern Syria since the civil war began in 2011.

A Russian bombing campaign against rebels including Turkey-backed rebel groups, however, now threatens to undermine Ankara's entire Syria policy, which has been predicated on bolstering anti-Assad rebels and establishing a "safe zone" for displaced Syrians.

It also precludes any possibility of Turkish intervention in the north.