What is the WORST that could happen to the economy?

Read the book "Patriots" by Rawles. 160 million will die as the US dollar becomes worthless and people begin killing each other for whatever food is left over. Cities will burn into ruins while armed gangs roam the countryside raping, pillaging, destroying and burning everything. The only survivors are the survivalists who for years have prepared for what is coming. In the end its called Civil War II and those that survive rewrite the Constitution to deprive the Federal Government from destroying the economy through deficit spending. During the chaos a group of politicians attempt to place themselves in power by using NATO forces on American soil to enforce their reign. They fail.