Could the long dollar slide be over? For the better part of the past decade, and particularly in the last few months, the American dollar has been the 98-pound weakling of the foreign exchange world. It has lost value against almost every other global currency — not just the euro, pound and yen but even the Romanian new leu and the Latvian lats. Driven largely by the Federal Reserve’s policy of printing dollars to help spur a healthy economic recovery that remains stubbornly elusive, the dollar, weighed against a basket of other currencies, hit a 40-year low this month. But...