Lots of folks are speculating about what Ukraine/Crimea/Russia is like, including not Abkhazia. Right now, the analogies that come to mind for me are: coups d’etat and poker.
Coup? Yes, because in a coup, the anti-incumbents (for want of a better term), move first, trying to create facts on the ground that are hard to reverse. If this fait accompli is successful, the incumbents are then put in a position where they are the ones with the pressure to use force. The onus is on them. Which is why Putin would be smart to stick to Crimea. Other deployments in Ukraine might mean trying to push Ukrainians aside, which would then put the onus on using force back on Russians.
Using force is a big step, and you (Putin, Ukrainian leaders, whoever) do not really know if the order will be followed. And if you order the use of force, and it is not carried out, then the thing collapses pretty quickly (yes, there are principal-agent problems here, damn it). So, the preference again is to force the other guy to face that tough decision.
Which leads us to poker. In poker, aggression tends to win. That is, betting big forces the other player to have to face a difficult decision–am I bluffing? Are my cards good but not great? In the past ten years or so of online poker, the lesson has been learned that hyper-aggression tends to work because it forces folks to have to make difficult decisions of risking their chip stack or waiting for a better spot … and they wait for a better spot, which means that the player who bet big wins the pot.
So, if we have to play the analogy game, and it is one that I both revile and embrace (I tend to teach via analogies), then let’s think about the situation as it is now: two sides facing each other, waiting for the other to blink. This is not the Cold War but rather Coup 101.