It’s no joke. The U.S. is threatening to slap a 100 percent tariff on European Union cheeses, and importers say the decision could come as early as next week. Brace yourself to pay double for Parmigiano-Reggiano, your holiday Stilton and Gouda. The targeted cheeses include most of what we get from France, Italy, Spain and the U.K. Importers and retailers are justifiably frantic. How can they place orders, print catalogs, run a business with such uncertainty? You can’t stockpile Brie.