Of course that's not all that's going on. North Ossetia is part of Russia; when Georgia broke off, it took South Ossetia with it. Russia thinks Georgia should be part of Russia, but if it's independent, there are difficult border disputes. South Ossetia's rebel government is pro-Moscow, but I have no idea if the population wants to be part of Russia or Georgia, or whether they want independence from both. (They're currently in a netherworld, independent but unrecognized.)
Not that I'm claiming to understand any of this. But another element of this situation that seems important is the shattering of the old Eastern Bloc into so many tiny countries. Georgia broke away from Russia, and then South Ossetia and Abkhazia broke off from Georgia. When Yugoslavia dissolved, Serbia got its independence, and then earlier this year Kosovo broke away from Serbia. Russia objected to Kosovo independence, and the US supported it.
It's hard to imagine that all this fracturing can lead to stability. Are the breakaway countries big enough to survive? I'm just guessing here, but you'd think that total independence would be a temporary situation, and would transition into alliances (like the EU) that would have them banding together into logical groups. The reason I mention this is that, if they are going to form stable alliances, it's not at all clear to me that NATO is the proper forum. In other words, Russia might have a point in objecting to the fracturing and the NATO envelopment.