… is from pages 120-121 of Paul Krugman’s excellent May 1993 American Economic Review essay “What Do Undergrads Need to Know about Trade? ”, as it is reprinted in Krugman’s important 1996 collection, Pop Internationalism  (link added):
One of the most popular, enduring misconceptions of practical men is that countries are in competition with each other in the same way that companies in the same business are in competition. Ricardo  already knew better in 1817. An introductory economics course should drive home to students the point that international trade is not about competition, it is about mutually beneficial exchange. Even more fundamentally, we should be able to teach students that imports, not exports, are the purpose of trade. That is, what a country gains from trade is the ability to import things it wants. Exports are not an objective in and of themselves: the need to export is a burden that a country must bear because its import suppliers are crass enough to demand payment.
Indeed. And, therefore, supporters of that great geyser of cronyism – the U.S. Export-Import Bank – are in reality supporters of increasing the size and weight of the burden that Americans at large must bear to engage in commerce with non-Americans.