One area where Paul Krugman is a genuine expert is currency crises - he claims with some justification to have invented the field of study in economics. Here he takes a look at the Russian debt situation.
He recalls the textbook responses:
At this point the approved move is either (a) go to the IMF or (b) invade the Malvinas. Somehow, (a) doesn’t seem likely — and Putin did (b) in advance.