It is the re-ordering of society.
It is the collapse of society itself that poses the single greatest threat to individual survival. You will have lost all that so many take for granted: medicine, housing, sanitation, civil order, food, industry, etc. The sooner a society is reordered to allow 1 person to provide for a particular need of many others the sooner they can commit to a mutually agreed upon set of laws and common defense, which in turn permit greater personal productivity.
If everyone resorts to subsistence farming then that is all they will ever accomplish. But if 1 farmer can provide for many than another can become a doctor to alleviate disease and injuries while others become manufacturers that can create machines and tools and yet again others become dedicated to the useful sciences. Collectively they will have enough free labor for their common defense and ultimately: expansion.
Remember, liberals think America is the most powerful nation on the earth because we stole everything from everyone else. We know better that we are a nation of laws, not men but all men are free to enjoy the wealth of their own labors. If that ideal got us here once it will work every other time it is tried. It's not an accident, it is a system built upon a historical view of human nature.