You are certainly correct, if maybe only in theory. At the rate things are going, good luck with any country freely harmonizing anything with the USA. The USA is more likely on a steady course of becoming increasingly less relevant to anyone but themselves.
A different president is not going to change that. The country's international policies (current and past), in particular its use of their relative economical and military power imbalance, have been abusive for way longer than just this last president. Ordinary citizens around the globe have become increasingly more aware of this, often from experiencing its unpleasant consequences. It already has become harder for many foreign politicians to keep giving in to US power play, to how it essentially treats the rest of the globe as its own territory. Expect things to get a lot harder for the USA.
Meanwhile, a growing group of people looks at the USA's internal affairs, wondering why on earth anyone would take any guidance or example from such a nation. I guess that plenty of US citizens will blame that all on the last president (certainly in part for very valid reasons), but the problem extends way beyond that. Regretfully, the USA just can't stop itself, for what it does internationally (mostly unknown to its own citizens).
Feel free to shoot the messenger .. it won't matter.