The euro crisis first started roaring in late 2009,
when auditors inside the newly elected Greek government discovered that
the country had a much—much—bigger deficit than anyone realized.
That,
in turn, inflamed fears that Greece couldn’t wiggle its way out of its
debt trap so long as it was tethered to the euro. It also exposed
structural problems within Europe’s currency union. Worries soon spread
to Ireland, Portugal, and eventually Italy and Spain. Now the entire
global economy is on edge.