On ships, it's a crime for members of the crew to abandon their posts in an emergency if there are passengers at risk. Similarly, when you are working for the government in some capacity I think you ought to be fully committed to it. If you prefer to put your own interests first, then stay in the private sector.

And yeah, I do think it's a bit of a problem that the United States doesn't have any real civil defense infrastructure in place although realistically geography largely insulates the United States from conventional military attack and so there's much less practical need for such options compared to countries in other regions.