What do you do?

Let's consider a hypothetical situation: A really scary dude who has a history of making his enemies disappear gets into a violent disagreement with a friend of yours. Then, the guy threatens to kill your little brother, who would have little chance of defending himself. Do you try to reason with the potential killer? Do you ask his friends to intervene? Or do you take the risk of trying to catch the guy in a dark alley and remove him with "extreme prejudice"?
Now, let's move to a real-world scenario: A clearly provoked Russia invades Georgia, a country friendly to the United States. It thumbs its nose at the rest of the world when the action is condemned. Then, it raises the specter of a nuclear attack on Poland, which has agreed to be the site of a U.S.-built missile defense system. Russian dictator Vladimir Putin, above, increasingly seems to be a guy who is a few sandwiches short of a picnic. Only he knows how serious the threat is. But what do we do about it? Do we try to reason with him? Do we ask China to do our bidding? Now, what about this: If we have reasonable certainty that we could annihilate Russia with our various weapons systems, most of which probably aren't even known to us, and that we could protect our own country from an annihilating response, should we consider a first-strike, pre-emptive "nuclear option"? We attacked Iraq when it really posed no threat to us whatsoever. Here is a country that is rattling sabers regarding use of nuclear weapons against a nation we have pledged to defend. And Russia has plenty of nuclear weapons that it could fire our way if Putin decides we are standing in the way of his plans for world domination. What's your plan for dealing with him?