Using Canada, the largest trading partner with America, and Mexico, the second largest trading partner with America, as examples; I think it's obvious that business as usual would be the expected norm, rather than some kind of cessation of trading among the states.
At what point were Canada and Mexico part of the US and said, "the heck with you"? The fact is that we trade with Canada and Mexico because they are established, soverign nations. A state that succeded would be SOL.
hogdogs, what is the base of the nutritonal pyramid? (Hint, it is grains) You do not get enough grain production to feed a southern state until you cross that Mason-Dixon line. I do recall that is one of the things that screwed the south back when their population about equaled that of GA(could be a little off, but hey).
BTW, Ports matter about as much as a fart in the wind when the US Navy comes to town. Besides that, no nation is going to risk PO'ing US government for the chumpchange a state/country could provide.
rhstockupontwinkiesgunguy
I think the larger states could make it on their own. California and possibly Texas could survive as independent countries.
Texas, maybe, but California? HA! What are they going to eat, Napa grapes, seafood(not enough to feed everyone due to anti-commercial fishing laws), Sonoma sno-cones and microchips? The coyotes would eat better on the corpses of starved Californians.