Vladimir Putin happily exploits all this, not just because he is an adventurer, but because he really does not believe in the post-Cold War settlement. In the 1990s, we in the West felt it had all ended happily once, with Russian co-authorship, “Helsinki” human rights and national democratic freedoms had been guaranteed across the formerly Communist Eastern bloc.

Putin’s Russia rejects this vision. It claims it was forced to accept it in a moment of weakness. The Russians’ view of the world is quite different from ours of a comity of free countries.

They seek a system like that constructed by the Yalta agreement of 1945, in which the globe is carved up into spheres of influence. Within its sphere, Russia would be free to oppress its subject peoples (in Estonia, Ukraine, perhaps even Poland) as it saw fit.

Putin has challenged the post-Cold War settlement so fiercely that you could almost say there isn’t one any more. The rules of the international system have broken down.