Interesting question. I think that most people, at least here in the USA, simply assume that Federal and State government agencies, augmented by non-governmental entities like the Red Cross, will eventually provide relief for large-scale catastrophes. That has been the basis of my long-term emergency planning. In other words, my preparation consists of stockpiling enough food, water, fuel, shelter, and medical supplies to last until relief comes. I have (somewhat arbitrarily) put this at two weeks. I figure that if aid does not arrive by that time, then it may not be arriving at all. I'm still trying to figure out what my fallback position will be then. Perhaps it is time to resusitate the old Y2K mentality -which I never bought into by the way- and stockpile a years worth of stuff like many of my neighbors do.

And yet I'm still pretty certain that, short of an asteroid/comet collision, help will be available and will arrive quickly.

Regards, Vince