Among those blindsided by Greece’s decision to call a referendum on the eurozone’s rescue package, count Barack Obama’s White House.

For months, the administration has been watching the unravelling of the various patched-together deals to save the single currency with a mixture of despair, frustration, annoyance, disbelief, and, for much of the time, helplessness, a sensation neither familiar nor welcome in the corridors of power of imperial Washington.

On top of the angst induced by the crisis in Greece, there’s also some understanding in Washington of the difficulties in forging a eurozone agreement and a sense of humility forged by America’s own deep fiscal problems.