The boundaries of all the Balkan and Caucasus states are ill defined, one blurs into the other, each contains people who feel themselves outsiders and oppressed. In some, like Estonia, “oppression†is merely that if you cannot speak the majority language, or a widely spoken international language such as English, you have poor job prospects. In others, oppression consists of robbery, rape, and murder. By and large the resentment is greater, and more likely to lead to bloody fratricidal violence, when it is merely a matter of not being able to get a job if people cannot understand what you are saying.
A lot of people that think themselves Ossetian and Russian live in Georgia. Most of them cannot speak Georgian. Imaginary repression resulted in bloody insurrection, which resulted in real and bloody repression. Russia intervened and seized what it now calls South Ossetia. It installed a police state there, which suggests that not all South Ossetians hate the Georgians more than the Russians.
Georgia proceeded to build up its military power, and had a stab at getting “South Ossetia†back. Russians then invaded Georgia a couple of days ago, to prevent Georgians from recovering “South Ossetiaâ€.
So it is not necessarily serious. Both sides might well accept a return to the status quo ante, wherein “South Ossetia†remains a Russian police state. Georgians, however, are perfectly capable of making the status quo painfully expensive for Russia, and have been doing so, which might provoke Russia to eliminate Georgia – or Georgians.