For the second year in a row, Cognac is experiencing a significant downturn in sales, perhaps as much as some 13 percent overall. Insiders chalk this up to China — Cognac’s biggest market by value — levying duties of up to 34.9 percent on European brandy, something widely viewed as retaliatory for the EU’s decision to impose huge import tariffs on Chinese-made electric vehicles. Similar tariff problems abound in the U.S. — Cognac’s biggest market by volume — and consumers seem t...