I think at this point he doesn't believe the west is going to say no. We've heard various western senior officials or government leaders say that there is no military option, that there's no military solution, so don't talk about military responses to this. As long as Putin hears that—and I know that he not only hears it; he believes it—then he thinks he can do what he wants.
Now, he's going to be careful about doing this. I think he may have learned a few lessons from his invasion of Georgia six years ago. He's looking to create appearances of legitimacy through referenda, through popular movements, people calling for Russian peacekeepers to come in, accusations that the government in Kiev is fascist. He's looking to create these veneers of legitimacy and legality that create a demand for Russian troops to come in.
I also think that he's going to try—and this is very World War II-ish—a pincer movement, where you have Transnistria in the west saying that it wants to be part of the Russian Federation, the eastern provinces in Ukraine saying they want to be part of the Russian Federation, and probably you'll see some demonstrations agitated in Odessa, which will demand some kind of Russian security presence there. I think you could see a very quick marrying up of Russian forces to, what Russia would say, restore order and protect the rights of Russian minorities in Ukraine.