US road expenditure is estimated to be about $250 billion a year.

Many places have gas at similar prices to the US (largely due to taxes, not imperialism).

While new vehicles are a huge resources suck (15 million new vehicles a year), it’s only about five to ten percent of GDP and would naturally dwindle in response to declining conditions.

On water insecurity, in 2014 Algeria opened a desalination plant for $500 million. It produces about 500 megalitres a day - so you would need three of them to give those 50 million Americans 150 litres (40 gallons) a day, assuming they were all in one place.

Arizona has more than enough water - 8.5 million megalitres in 2017, of which 72 percent went to agriculture.

But let’s say you had to move them because US land use and infrastructure is legitimately the worst - you could stick them in an area the size of Slovenia, assuming the density of the Netherlands, on the west coast here:

I think that’s the real problem for the US - it’s a naturally rich place but the infrastructure and planning is completely broken. Take healthcare, one of the largest single sectors, gobbling up 20 percent of GDP to deliver generally worse outcomes at twice the cost as other western countries.

All basically fixable with a command economy and average resourcing.

Surely even Americans would revolt if the lack of imperial profits heightens contradictions as capitalists intensity domestic profit extraction when the US hegemon is dead.