Trust, but verify Trust, but verify Trust, but verify (; "Doveryat, no proverit") is a Russian proverb. The phrase became well known in English when used by President Ronald Reagan on multiple occasions in the context of nuclear disarmament. Suzanne Massie, an American writer, met with President Ronald Reagan many times between 1984 and 1987. She taught him the Russian proverb "Doveryai, no proveryai" (; "Trust, but verify"), advising him that "The Russians like to talk in proverbs. It would be nice of you to know a few. You are an actor – you can learn them very quickly." The proverb was adopted
US signals intelligence in the Cold War units in border areas." In the fifties, only aircraft platforms could obtain SIGINT over the USSR. A Soviet source pointed out that aircraft were of limited usefulness, due to being vulnerable to fighters and antiaircraft weapons. (Translator's estimate: in the period 1950-1969, about 15 US and NATO reconnaissance aircraft were shot down over the USSR, China, the GDR and Cuba). The US, therefore, undertook the WS-117L reconnaissance satellite project, approved by President Dwight D. Eisenhower in 1954, within which was a signal intercept subsystem under Project PIONEER FERRET. By 1959, WS-117L had split into three programs: The first experimental ELINT