Next, Putin Will Seize Donetsk and Kharkiv

As Russian troops consolidate their hold over Crimea, it seems clear that President Vladimir Putin will soon have troops in eastern Ukraine as well. The Federation Council passed a law giving Putin broad authority to use the country's armed forces on "the territory of Ukraine," and this, in combination with pro-Russian demonstrations now spreading across major eastern cities, provide Putin a fig leaf necessary to move into eastern Ukraine.

While many Western analysts — and even U.S. intelligence agencies — predicted that Putin would not move on Ukraine, they have clearly not understood Putin's worldview. Russia looks at Ukraine in the same way that China looks at Taiwan: as an existential issue in which lines must not be crossed. The West has missed four crucial points:

For Russia, Ukraine is the birthplace of Russian civilization and a close Slavic brother. The idea of Ukraine as an independent country aligned with the West is anathema to Putin. Many Russians refer to Ukraine as "little Russia." This is best encapsulated by an April 2008 conversation Putin had with then-U.S. President George W. Bush in which Putin reportedly said: "You don't understand, George, that Ukraine is not even a state. What is Ukraine? Part of its territories is Eastern Europe, but the greater part is a gift from us." In Putin's view, Western support for the anti-Russian protests in Kiev is part of a Western plot to tear Ukraine away from its proper place next to Russia's cultural, political and economic bosom. The West should have understood that there was no way Putin was ever going to allow Ukraine to slip away.

The West has grossly underestimated the extent to which Russia was humiliated by NATO expansion toward Russia's borders in the 1990s. From Russia's perspective, NATO's eastward expansion evoked deep-seated Russian fears of being both encircled and shut out from Europe. Russia has suffered numerous invasions from the West, and in Putin's mind even a European Union association agreement is a possible precursor to eventual NATO membership. Ukraine is Putin's line in the sand.

It is often said that with Russia is an empire as long as Ukraine is in its camp, but without it, Russia is just another regular country. The reality is that for centuries, Russia has been an empire, and an expansionist one at that. While we can debate the reasons for this, the reality is that Russia has never seen itself as just a regular country, and for that reason Russia will always ensure that Ukraine is firmly within its orbit.

Finally, Putin has decided to move on Ukraine now simply because he can. Putin knows that there is little that the U.S. or NATO can do to prevent him from having his way with Ukraine, and he is right. Short of risking war with a nuclear Russia, Putin is fully prepared to ignore any Western threats of "costs" that Russia must pay for seizing parts of Ukraine.

For these ideological, historical, military and geopolitical reasons, it is natural that Putin will not stop at the borders of Crimea. Putin will almost certainly not move into western Ukraine, but in the south and east where the population identifies strongly with Russia, there will never be a better opportunity than now to reclaim what Putin considers to be lost Russian territory. By next weekend, we very well might see Russian troops patrolling Kharkiv and Donetsk, and they won't be leaving anytime soon.