Quote Originally Posted by Dayuhan View Post
In short: the US has every reason to be concerned, no reason whatsoever for fear, panic, or hysteria. I don't think it's at all likely that Putin can be forced to give back Crimea, but it is likely that he can be deterred from taking another bite... unless he's presented with an irresistible opportunity, which should be avoided. The US needs to work closely with Europe, urge them to adopt harder sanctions if needed, but not try to dictate what the response should be. I think bluster is pointless and counterproductive and that no demands should be made that we haven't the will or capacity to back up with action.
So Putin called Obama to reach a “diplomatic resolution”. Earlier I wrote, looking at Russias short economic legs and Clausewitz that:

Russia wants of course peace now and de-escalation after having annexed unopposed a weak and defenseless province because it's politicians, lacking power and military means, (rightly) feared a bloody decision and an even worse outcome.
Now, as you have pointed, nobody knows if Putin wants to grab another piece of land and create that 'worse outcome'. But it is very likely that the costs in blood and Russian wealth will be considerably higher if he decides to invade Ukrainian mainland and that Putin knows it. However if he is able to get peace now the patriotic victory should not lose too much glory at home and in some abroads.

On the other hand he should know that even a mighty Empire with the largest mechanized army the world has ever seen can implode in the circumstances of economic catastrophe and collapse...