Masked Russian troops have moved into Crimea, with unmarked uniforms and heavy arms. Some of the residents cheer them, while others fear them. And they may be the undoing of the delicate ethnic balance in Crimea.
Michael McFaul spent years living in Moscow as the US ambassador, with a front-row seat to the diplomatic dance between the US and Russia. Now, he's come home, but he remains fiercely interested in what's happening in the region. Especially with Ukraine.
Russia's military moves since the fall of Ukraine's government last week seem to signal one thing. Russia is not prepared to lose the Crimea. And the reason is pretty straightforward, if you look at history.