Ever wondered why Putin invaded? Crazy or was there any method to the madness?

David Sachs is a brilliant historian and Director of the Center for Sustainable Development at Columbia University. For the past several decades he's advised many US presidents and was a special advisor to the UN Secretary-General.

I can think of few Americans more familiar with the history of the Soviet Union or it's breakup. If you want to understand exactly why Putin invaded spend 5 minutes on this video.

The lesson from this is you should not needlessly poke the Bear. You won't like the results.