For insight into the Trump's truly astonishing ignorance, this annotated script of his telephone conversation with Australia's Malcom Turnbull is an eye-opener:
https://www.vanityfair.com/news/2017/08/the-trumpian-dealmaker-myth-is-finally-truly-dead

It is impossible to conceive how this idiot would go about "renegotiating" international trade deals, but based on the first six months of his presidency, I predict he won't even attempt to do so.

Stephen J. Remington