Byzantium was in decline for seven centuries until the Ottomans pulled the plug. Rome was in decline for several centuries prior to its sacking.
Climate change and the accompanying plagues, droughts, famines, and calamities that accompany it might accelerate and exacerbate the state's capacity and willingness to respond to these crises, but all it might mean is that this is a new normal added to the reproleterization of American life.
I don't really have a point but it is just a thought that I (perhaps others) are going to have to accept that future, and that is a kind of new world I am unsure as to how to adapt to.
I mean... it's socialism or barbarism, quite literally. The US's decline won't be a Soviet-style collapse into multiple states or lawlessness - that would most likely be the end of the world, given our military.
Absent socialism, it will be a further descent into the oligopoly we have now without the pretenses of freedom and democracy. Liberals in power are too scared to do something like go house to house confiscating guns - but an American Falange wouldn't. Mass deaths from hunger or war will be normalized, probably extrajudicial murder gets completely legalized.
Dude, whenever I think about US balkanisation I just end up thinking about who the hell is gonna end up getting nukes on their hands.