They now have control of a path through the Caucasus mountains. If it looks like an attack on Iran is immanent, they have the ability to drive convoys through Georgia and Armenia to Iran.
Would the US or Israel attack Iran with Russian troops on the ground in Iran standing on top of high-value targets?
Absolutely.
Russian conventional forces wouldn't stand a chance against American armor or US and Israeli airpower.
Nazi Russia is taking a huge gamble, hoping that an outgoing Bush administration will not stand up to it and that any new administration will be weak.
The only thing that can save Russia's strategy is for the USA to lose its nerve.