The United States' monopoly on nuclear weapons was broken by the Soviet Union in 1949 when it tested its first nuclear explosive, the RDS-1. With this, many in the US Government, as well as many citizens, perceived that the United States was more vulnerable than it had ever been before. In 1950, during the first big Civil Defense push of the Cold War—and coinciding with the "Alert America!" initiative to educate Americans on nuclear preparedness, the adult-orientated Survival Under Atomic Attack was published. It contains "duck and cover" or more accurately, cover and then duck advice without using those specific terms in its "Six Survival Secrets For Atomic Attacks" section. "1. Try to Get Shielded 2. Drop Flat on Ground or Floor 3. Bury Your Face in Your Arms ("crook of your elbow")". The child-oriented film "Duck and Cover" was produced a year later by the Federal Civil Defense Administration in 1951.