A very good summary of things. It does get worse for the USA from here out. We put up with moderately abusive one sided agreements with the USA because we looked at the big picture and we were still better off even when the abuse was factored in. We overlooked the low productivity and high debt in the USA because the system was generally working. So as we move away from a system with the USA at the center, since it has lost its stability, and replace it with "greater cooperation between the world's middle powers and other smaller countries" where does that leave the USA?
The answer does not look good for the USA. If the USA was successful in closing itself of the world what would the world lose? Move your email away from gmail and find a new search engine? Well if it happened overnight we would find there are other things we do actually need from the USA today, but given the process of isolating itself from the world will take the USA a while we have time shift to getting what we need from more trustworthy countries.
The thing that people in the USA often overlook is how much debt they have. Look at what is happening to US bonds, other countries are backing away from them. trump is right that the trade imbalance is an issue, but wrong to blame it on abuse of other countries instead of the real reason, the growing debt the USA is taking on. I guess after trump has bankrupted so many companies it seems fitting that his legacy will be to be the person who finally bankrupted the USA.
Am I rooting for the downfall of the USA? No, but I had been hoping that once things got bad enough the people of the USA would take a cold hard look at their place in the world and up their game. Kind of like that low point that some people have to reach before they turn their life around. The sad part is there is no sign that the majority people in the USA have been able to see the big picture yet. They still live in an information bubble that feeds them American exceptionalism so the spiral downwards continues and the rest of the world is pulled down with it as we work to isolate ourselves from it.