Remember, Russia has not (yet) formally annexed the territory that Russia stripped from Georgia in 2008.
And Russia's creeping annexation of Belarus is an ongoing process of gathering power and control while reducing Belarus' effective autonomy.
Putting Russia on the road to that increasing level of control in Crimea by ejecting Ukraine from the territory while agreeing to a fiction that Crimea is some sort of semi-independent dependency of Russia is a win for Putin.
UPDATE: These are good words from our president:
President Barack Obama ordered the West's first sanctions in response to Russia's military takeover of Crimea on Thursday, declaring his determination not to let the Kremlin carve up Ukraine. He asserted that a hastily scheduled referendum on Crimea seceding and becoming part of Russia would violate international law
So we've set an orange line against accepting Ukraine's loss of Crimea. I guess there are a couple questions. Does Putin believe President Obama's words?
And does President Obama believe them?