It's anyone's guess how Russia will act in Ukraine over the coming days and weeks. The New Yorker's David Reminick, who spent years reporting out of Russia, and who recently wrote a fascinating analysis of Putin's worldview, argues that the situation could get much worse before it gets better. To justify the invasion of Crimea, the Russian parliament "repeatedly echoed the need to protect ethnic Russians in Ukraine — a theme consonant with the Kremlin's rhetoric about Russians everywhere, including the Baltic States," he writes. "But there was, of course, not one word about the sovereignty of Ukraine, which has been independent since the fall of the Soviet Union, in December, 1991."
If this is the logic of the Russian invasion, the military incursion is unlikely to stop in Crimea: nearly all of eastern Ukraine is Russian-speaking. Russia defines its interests far beyond its Black Sea fleet and the Crimean peninsula […]
It's also worth noting that, in 1968, Moscow was reacting to the "threat" of the Prague Spring and to ideological liberalization in Eastern Europe; in 1979, the Kremlin leadership was reacting to the upheavals in Kabul. The rationale now is far flimsier, even in Moscow's own terms. The people of the Crimean peninsula were hardly under threat by "fascist gangs" from Kiev. In the east, cities like Donetsk and Kharkov had also been quiet, though that may already be changing. That's the advantage of Putin's state-controlled television and his pocket legislature; you can create any reality and pass any edict. [The New Yorker]
So far, the U.S. and other Western powers have condemned the Russian incursion without calling for forceful consequences beyond sanctions. That could change if Russia indeed decides to solidify its grasp on Crimea, or push on into Ukraine.