By the time an interpreter gets into a room with the president and a foreign leader, he or she brings in more than simply past meetings. The first, essential foundation is a wide range of general knowledge. White House interpreters are provided by the Office of Language Services, which tests would-be interpreters on general knowledge.
“To work at the very top, you have to have an incredible arsenal of general knowledge, because the president will get into every damn topic you can imagine, from nuclear submarines to agriculture to treaty problems to labor problems to God knows what, jellyfish in the sea,” Obst says. “If you don’t know how an airplane flies, if you don’t know how a nuclear reactor works, you’re going to make mistakes.”
Like anyone else in a sensitive meeting, an interpreter must have high security clearance. He or she will also have received all the same briefing books as the president. That’s essential so that the interpreter can understand the nuances of the information discussed and knows the vocabulary. But it also means that the interpreter can serve as a crutch for the president, catching minor factual errors or slips of the tongue.