I'll just say quickly, he doesn't believe that western Europe will really apply very tough sanctions against Russia. So he thinks that his market is Europe, but that they are so dependent upon Russia and so cowardly or so lacking in political will that they won't take the steps necessary to really push hard, and if they do, then he can negotiate them back while still keeping Crimea and whatever else he's taken up to that point. I think he is calculating this, as you say, but very aggressively.
On April 7th, 2014. See this statement in context.