Any college-level financial-history class includes at least one reference to Argentina, and potentially many more. The lesson is too tempting. Very few nations have experienced the kind of de-development that afflicted the southern republic, taking it from a wealth level comparable to those of Canada and Australia in 1900 to financial ruin a century later. And yet, after a momentous election in 2015, Argentina has made a triumphant return to capital markets: Investment is flowing in, inflation is declining, and growth is accelerating. The Economist has just celebrated Argentina as one of its “countries of the year” (though the magazine …