The devil went down to Georgia

There is a lot of oil and gas around the Caspian Sea.  The problem for producers is getting it OUT of that area.  It is bordered on the south by Iran, on the east by Turkmenistan, on the northeast by Kazakhstan, on the northwest by Russia, and on the west by Azerbaijan. 

One quick way would be to get it to ports in the Black Sea through Azerbaijan and Georgia. 

Ossetia  https://en.wikipedia.org/wiki/Ossetia

The region of Ossetia extends over both sides of the Caucasus mountains, which, on the north side was in Russia and on the south side was in Georgia.  In 2008, separatists in South Ossetia “broke away” from Georgia.  North Ossetia didn’t try to become independent from Russia, though, and the newly “united” Ossetia quickly (re)joined Russia, which graciously accepted to annex them.

At the time, there were 3 oil and gas pipelines from Azerbaijan to the Black Sea, two of which ran through South Ossetia.  By acquiring this area, Russia now controlled two of them