The key questions to ask here are what, if anything, would replace the federal government, and what's causing the federal government to dissolve? "The 50 states all become independent countries" isn't feasible because many states aren't viable as independent countries
1.there are a lot of currently independent countries that aren't viable
2.I'd assume there would be new, smaller, Federal entities formed in the various regions, certainly some currency sharing would be in the works*
3.lists have three things
*the ways this is going to play out in the midwest states with big cities is going to be interesting. I could see a further fracturing of states if such a situation were to play out. It could get ugly fast. Imagine if 85% of Illinois left the state of Illinois because they hated Chicago and Chicago tried to use force to bring them back inline?