Putin and Obama hate each other at this point I reckon.
Putin has Barry’s number and Barry knows it. And no fawning press or fake marble columns to put a nice face on it.
Depends on how intense the feeling is. If it's the kind of emotion expressed when one child says to another "I hate you" - no skin off Putin's nose. If Obama really hates Putin, and wants to take him down a peg, he can do so without a single GI ending up in a body bag. If Ukrainians are willing to fight, all Obama has to do is provide them with weaponry and training. The Russians will eventually fold. And Obama can say he did it without putting any GI's in harm's way.
The president of a country with the biggest economy in the world, and close to 50% of the entire planet's military spending, has tons of options at his disposal, well short of putting boots on the ground. It's not of question of will, since there's no real political or economic sacrifice involved (a few billion a year is a rounding error in political terms), but a question of inclination. If he does despise Putin, I bet he's waiting for the Russians to draw first blood before doing anything on the material aid front.
People are gonna be blindsided, but I have a feeling this is Putin's unwitting present to Obama for the 2014 mid-terms. In retrospect, people are gonna say Putin was idiotic to put his head in the noose, knowing that Ukraine can make possession of the Crimea too costly over years without any outside material help, and prohibitively expensive over months with outside material aid.