I’m with CPT Charles and John Samford.

Putin clearly has designs beyond South Ossetia. This is just the first round.
Putin and his KGB friends dream of Empire in the worst way. The KGB wants to bring much more of European territory within its realm, whether by force, extortion, or intimidation.

Putin’s motives may not be fully rational or fully thought out. What kind of rational actor forms a tacit alliance with the nutters in Tehran to help them get nuclear weapons?