Russia no longer has jurisdiction over them, but of course there is motivation in aggression because of the history and subsequent independence. But, this doesn't mean Russia is the guilty party here, it's more complicated than that. Although you and me don't hear about it this was has been brewing for almost a decade.
Basically Russia came to the call of South Ossetia because Georgia sent in troops to silence the separatism.
You can't blame Russia: Georgia seemed to think it was OK when they rebelled against Russia to gain independence, NATO OK'd the Serbian split (which is potentially more damning as non-muslims are moving out of Kosovo due to islamism) so Western Nations really can't criticise.
So basically:
Georgian troops try to quell separatism -> Fighting starts -> Russia come to the aid of South Ossetia -> War starts
Nordic,
I usually agree with most of your post on GetBig, but not this time.
The facts :
Russia wont allow Chechnya to break away from them (Russia) and become independent, yet Russia demands that another Country (Georgia) must allow part of their land to break away and become independent. Hypocrisy at its finest!
Russia is trying to show the other FSU's what happens to a Country that is pro-west and wants to become part of NATO. They are currently doing the same to Ukraine by tripling the price of natural Gas, as a penalty for electing a pro-west President. And doing this after first having him poisoned.
Also just like the ex-KGB guy that Putin had poisoned in England, they wanted to show the world that no place is too far, that they cant get someone who they think is a threat.