I will not explain to you what is happening in Kiev tonight other than to say that it is Vladimir Putin's worst nightmare.

The last time that this many people came out to the Independence Square (the Maidan) in Kiev, nine years ago, protesters undid the election of Victor Yanukovich and brought to power a Western-friendly government. In the process, they scared the living daylights out of Putin. The reforms he began at the beginning of his term to limit electoral competition, sideline his critics, disable civil society, and atomize the population took on a renewed urgency. Out of the turmoil in Ukraine in 2004-2005 came the strange Russian concept of "sovereign democracy" (our way, when we're good and ready, i.e., never) and the often terrifying pro-Kremlin youth group Nashi run by a man who used to run with a gang that beheaded its victims.



There was a wave of color revolutions in the former Soviet Space around then, in Georgia, in Kyrgyzstan, but the Orange Revolution in Ukraine was different because Ukraine is different. Ukraine is Slavic. Ukraine speaks Russian, even though the Western part insists on having its own tongue. Kiev is the cradle of Russian civilization. Ukraine, in Putin's mind, is almost just another province of Russia, one that, by some accident of history and politics, has a different government and a different name. He is said to have said as much to George W. Bush in 2008. "Don't you see, George, that Ukraine is not even its own state?" he is reported to have smirked.

If it can happen in Kiev, in other words, it can happen in Moscow.

When the pro-democracy protests broke out in Moscow in the winter of 2011-2012, I sometimes wondered why the police would so violently clear winter sit-ins in subzero temperatures when it seemed obvious that, give them a few hours, and the prosters would get sick of standing knee-deep in the snow and go home. Or why, for example, the police bothered to arrest two former members of Pussy Riot today. Why sweat the small things?

But Putin and the system he built do sweat the small things because Putin sees dissent as a slippery slope. He knows the cold has never stopped a single Russian revolutionary. One day people are camping out in a snowy fountain in Moscow, the next they've set up camp and put up barricades in the center of town, bringing traffic to a halt, sowing chaos, and toppling the government. It is the authoritarian take on the broken windows theory, turned upside-down.