Well John seems to understand the significance of this action by Russia. I’ll bet he doesn’t share your view of what we should do right now. And that’s the problem. In the end, his views won’t have caused him to do anything more than Obama would in this situation, most likely nothing.
If we're being honest, we would have to recognize that in their current jobs neither Obama nor McCain has any power to "do anything" in any case. The only way they would, is if the crisis in Georgia (and perhaps beyond) extends beyond January of '09.
The best either of them could do in the next few months, would be to agitate for a Senate resolution condemning Russia's actions.
Given that they're both effectively powerless for the present, the only thing they can do is to use this as a means to distinguish themselves from one another.
From that perspective, I think McCain is doing a good job of setting himself apart from Obama. He's making clear that "history is back," and we need somebody who is equipped to deal with it.