CAMBRIDGE – In case you blinked, the Argentine government built up a pile of debt out of almost nothing with surprising speed, and then proceeded to default on it almost as quickly. Compared to the country’s slow-motion 2002 default, the latest crisis feels like 60-second Shakespeare. But in both cases, default was inevitable, because the country’s mix of debt, deficits, and monetary policy was unsustainable, and the political class was unable to make the necessary adjustments in time