South Ossetia

It's anyone's guess what the Russians' ultimate goals are, but I suppose there are three possibilities, in ascending order of seriousness.

First, simply to defend the (independence of the) South Ossetians, which is their ostensible motive. If that's the case, one might reasonably ask if invading Georgia is the right way to go about it. However the ultimate consequences might not be all bad.

Second, to annexe South Ossetia. No doubt pliant S.O. nationals could be found to publically thank them for doing so. This would definitely qualify as adventurism, and its successful accomplishment would likely increase the Kremlin's appetite for more such moves - Abkhazia probably being the first.

Third, a full-scale and prolonged occupation of Georgia, leading eventually perhaps to: the incorporation of large tracts of its territory (South Ossetia, Abkhazia, and the corridor between them) into Russia; the emergence of rump Georgia as a vassal state; or even the complete annexation of Georgia. This would be extremely bad, and would likely lead to instability in the surrounding areas.

Something that would worry me very much if it happened after successful Russian action in S.E. (defined as the second or third possibilities above) would be a coup in Serbia, followed by an invitation to Russia to safeguard Serbian borders. Conflict between Russia and the EC would seem likely at that point, followed almost immediately by a Russian energy embargo and a collapse of European will.