Maybe there are nations "backing" each of the factions who are their primary benefactor unless they have like a crime ring to support them?
This might be a thing, but for any major commercial activity the best anyone'd hope for is support with weapons and shit. But this boils down to who which nation would prefer. On a broader scale most reasonable great powers - the UK and western Europe most likely, Mexico and Canada too - may actively be seeking a diplomatic solution to the conflict to stitch America back together again. So in order to not perpetuate the conflict military aid may be minimal as well, or out of necessity flowing directly to the old "legitimate" government of the United States to strengthen their position against imposing odds and instability. The international community's response to the war would be, with the exception of China, Russia may stay out of it is trying to put the old US back on track to maintain the old balance of power.
A model we'd have to be looking at would be the Russian Revolution and the old Ten Days That Changed the World. Global powers would be funneling resources into the US, but only to try and back up the old government in the same way the UK and US tried to give the White Army or Russian Republic material support to combat the Bolsheviks, and then as soon as the war was lost had to go back in with their armies just to recover the stuff they sent to the old provisional or imperial government to keep their stuff from getting into the hands of the new government.
Commercial cooperation with groups would be comparable to trying to buy oil from Northern Kurdish Iraq, they'd have the supply there but political competition from other nations or factions that can get in the way would make actively buying anything impossible or so frustrated it's not worth it large-scale. So like competing over the flow of internet data through the physical land-lines of the US, everyone would be throwing themselves at stopping the other person from turning the valves to the outside world on to actually get any material benefit.
Interestingly,
@ClocktowerEchos would probably control all Trans-Atlantic communication over the internet. The giant-ass bundle of cables laid in the Atlantic to move internet traffic from east to west flow into his territory. That means the BBC, AlJazeera, and other European or whatnot outlets and means of communication would begin and end there in America.
California would probably control Trans-Pacific communication.