The fallout-shelter-network proposal, mentioned in the film, with its inherently high radiation protection characteristics, has similarities and contrasts to that of the very real and robust Swiss civil defense network. Switzerland has an overcapacity of nuclear fallout shelters for the country's population size, and by law, new homes must still be built with a fallout shelter. If the US did that, it would violate the spirit of MAD and according to MAD adherents, allegedly destabilize the situation because the US could launch a first strike and its population would largely survive a retaliatory second strike (see MAD § Theory).