The Day After played a major role in affecting world policy on nuclear weapons. Ronald Reagan had previewed the movie on October 10 1983, a month before it would be aired on TV. He had this to say in his diary:
In the morning at Camp David I ran the tape of the movie ABC is running on Nov. 20. It's called "The Day After" in which Lawrence, Kansas, is wiped out in a nuclear war with Russia. It is powerfully done, all $7 million worth. It is very effective and left me greatly depressed. So far they haven't sold any of the 25 ads scheduled and I can see why. [...] My own reaction: we have to do all we can to have a deterrent and to see that there is never a nuclear war.