Russia invades Georgia. And the US does what?

The Georgia invasion did make the two Sunday pundit shows, after discussions of banking reforms and the John Edwards scandal. Give the pundits that much. But no pundit really grasped what's going on here. The Russian army is invading a European country that is a US ally. If the US does nothing, (diplomacy is nothing) then the entire world learns that what the Russians want, the Russians get, and resistance is futile. If the US sends troops to defend Georgia, like we did for Kuwait, then we risk getting into a shooting war with the Russians. Both alternatives are horrible.
It's clearly up to the US. The Europeans are already scared of the Russians, except for the British they lack an effective military, and they are divided politically. They aren't going to tell the Russians to pull out or else. Maybe, with strong US leadership, a few of them would help us out a little, but that's about all. The disasters in ex-Yugoslavia (the Balkans) since Tito's death demonstrate what happens when it's up to the Europeans. Namely nothing.
For America, we are between a rock and a hard place. Nobody wants to get into a scrap with the Russians, at any time. For the fifty years of the Cold War we managed to avoid putting American troops within shooting distance of the Red Army, lest an outbreak of firing escalate into the Last Nuclear War. That's still a good policy. You don't crack open the door to Hell just to see if the fires still burn down there.
On the other hand, the Russians are taking South Ossetia today, and next step is all of Georgia. If we rushed a US division into the Georgian capitol (Tbilisi) tomorrow, the Russians might settle for promises of protection for the Russians living in South Ossetia, as opposed to conquering all of Georgia. Might.
The Russians want all of Georgia to gain control of the BTC pipeline, the only way to get central Asian oil out to the West. Look for crude oil to jump back up to $150 a barrel as soon as the BTC pipeline is closed to the West.
If we let the Russians conquer Georgia, it will give them the green light to take over all the over places that used to be part of the old Soviet Union, Ukraine, Belarus, Latvia, Estonia, Lithuania,Poland, Hungary,Czechoslovakia, Armenia, Azerbaijan, and all the rest of the 'stans. The Russians mean to reverse the enormous loss of territory that occurred at the breakup of the old Soviet Union back in 1989. If we don't oppose them, it will happen. After re acquiring their empire, what next will they try? They would be in a position to restart the Cold War.
McCain has called for resistance. Obama favors "diplomacy". I don't like either alternative, but I'm inclined to reluctantly back up McCain.