The point Zeihan makes is that world trade as we know it a recent invention. It exists purely as a result of the US commitment to protect trade from piracy around the world. Prior to that, the system was one of isolated empires each protecting their own routes.
As the US is largely self-sufficient in energy and will likely start becoming self-sufficient in a great many things, it needs the rest of the world less and less.
Those shipping lines, which mainly benefit the rest of the world, start to look like an expensive relic with each passing year.
All it takes for an end of shipping is for the US to stop protecting shipping lines which mainly benefit foreign governments.
I'm going to be very bold here, and say thats almost entirely incorrect. Any empire in the last 2000 years has depended on global trade. Before empire, in the bronze age, there is evidence of international trade.
> it needs the rest of the world less and less.
If we ignore the part where its almost entirely untrue that the USA is becoming self sufficient(its not, there is a reason why the Dollar is the international trade currency), It needs the world to export to.
> Those shipping lines, which mainly benefit the rest of the world
The things that stop global trade are disasters, wars, or weird autocracy fetishes (see expelling jews(middle ages), WWI, James I & Charles I being inept, north korea.) not "the natural order".
As the US is largely self-sufficient in energy and will likely start becoming self-sufficient in a great many things, it needs the rest of the world less and less.
Those shipping lines, which mainly benefit the rest of the world, start to look like an expensive relic with each passing year.
All it takes for an end of shipping is for the US to stop protecting shipping lines which mainly benefit foreign governments.