Russia's Iraq?

You may not have noticed between the Olympic news, the Presidential race, bank failings and nelebrity news, but Russia invaded the Former Soviet Republic of Georgia. Since something like 85% of Americans can't find Iraq on a map I doubt most people could tell you where Georgia is, or the history of the former Soviet Republic. The BBC has a map on the bottom of this article if your curious.
What kind of country would invade another for an oil pipeline?