Duck and Cover in case of nuclear attack was still being taught as late as 1985, or at least it was in my elementary school in TN; in fact, we got some of the old Civil Defense training, such as was suitable for children our age. By the time I was in a California high school, though, the Berlin Wall had fallen and the USSR was on its last legs; nobody thought that duck-and-cover would be useful in a CD role (though it was still taught for earthquakes only)