DanM wrote: “I keep coming back to Iran… That is where the global stage is focused. Russia has at least given tacit support to the mullahs. Why, in that context, does Russia open up a “2nd” front? The railroad is key, perhaps?”

The following is of course nothing but wild speculation.
DanM, how about the Georgian military bases and airfields? I am still wondering whether the Russian government might have thought that Georgia might have lent a helping hand to US and/or Israeli war preparations against Iran. There are Israeli military advisors in Georgia right now. Are they doing more than merely training the Georgian army?

It is not that far to Iran from there…