Big-power politics apart, the step was entirely logical within the dynamic of the evolving and mutating conflict in Syria.
The Russian intervention is a game-changer which opens a new chapter in the ever-escalating Syrian saga and lifts it to a yet higher level of crisis.
It carried a clear message: Russia will not allow the regime of Bashar al-Assad to collapse, although Moscow insists it is not wedded to him in person.
Until the Russians threw him this lifeline, it seemed as though the embattled Syrian leader was doomed.