Some forecasters are confidently predicting a large further rise in the U.S. dollar against key currencies like the euro and the yen. And a few ominously warn of impending currency wars where central banks outside the United States will manipulate their currencies to gain a global trade advantage.

Not so fast. First, currency forecasting is a hazardous business. And second, even if (as widely projected) the dollar were to rise substantially, its appreciation would seem consistent with relative growth prospects, not currency management by policymakers.