just a theory here
ive always been led to believe a possibility is, if we have another severe war the president and key personel board Air Force One and fly around until they sort things out and get to a safe haven
but it occured to me a possible safe haven could be the space station or a similar set up
tests have already been done on people spending great lengths of time in space
Astronaut Who Spent the Longest Time in Space on a Single Flight
The cosmonaut Dr. Valeri Vladimirovich Polyakov spent 437.7 days aboard Soyuz TM-18 (1994 -1995).
http://www.enchantedlearning.com/explorers/spacefirsts.shtml
the president or maybe NWO people or whatever could spend over a year in space while we all kill each other giving them more leg room when they get back
i have no evidence that this will happen im just opening a discussion