If you're eating Vietnamese food, then you're probably eating fish sauce in some form or other. Fish sauce, along with sweet and spicy Sriracha sauce (also known as "rooster" sauce for the rooster illustration on the label), make up the "salt and pepper" in traditional Vietnamese cooking.
Fish sauce is a condiment made from fermented fish,such as anchovies, which has been made in Vietnam for centuries. To many it has a distinctly pungent odor, but to the Vietnamese it is an essential part of their national identity. For example, when Alex first came to dinner at my parent's house for a traditional Vietnamese meal we all anxiously watched him dip his chopsticks into the bowl of Nuoc Mam, which is a dipping sauce made with fish sauce. I think we all collectively sighed with relief when it became apparent that he liked it. No one, of course, told him he was eating fish sauce that day. Many Vietnamese attribute the defeat of the Americans in 1975 to fish sauce, claiming that arms smuggled in barrels of fish sauce with their pungent odor kept them away.
Fish sauce was available in Europe before the war, but with the US embargo Thai producers of fish sauce entered the US and European markets. Phu Quoc is like the Champagne region of fish sauce and its product has been protected from imitation in France since 2002. France's ‘Cognac' name of origin has just been registered in Vietnam resulting from a cooperation program between Vietnam and France regarding the protection of names of origin and combating counterfeit goods with the assistance of the European Union. The Vietnam-France agreement provides for the protection of registered trademarks of Vietnam's Phu Quoc fish sauce and France's Cognac whisky in the two countries. France has also agreed to help Vietnam protect its fish sauce on the EU market.