I suspect that Putin now finds himself with a big, big problem over this foul atrocity; and, up to this point, from his point of view, the Ukrainian situation was all going reasonably well.

There is no doubt that the revolution in Ukraine presented Russia and Putin with big problems. The most urgent and pressing was the potential for losing the warm water ports of the Crimean peninsula. Putin acted quickly, decisively and ruthlessly and annexed Crimea. This was almost certainly an illegal act but who was going to stop him?

Eastern Ukraine represented a bigger problem but Putin took the route of arming Russian-speaking Ukrainian separist insurgents (the sort of thing that the west regularly does in other parts of the world). The trouble is, as the west regularly finds, such insurgents can be unpredictable, ill-disciplined and impulsive. Now they've gone and shot down a civilian aircraft with missiles that Putin, almost certainly, supplied them with. Whatever the truth of the matter is, most of the world community is pointing the finger of blame at Putin and Russia. What are you going to do, Vladimir? For all our sakes, it better be something good!