I think this relies on the demonstrably false idea that Iran has a nuclear weapons program. That's imperial propaganda. The Obama Iran deal was definitely extortion, but I think there's a clear case that it gave Iran more room to operate than the previous relationship did; the intensive nuclear standards and inspections were restrictive and obviously unfair, but the deal as a whole was less restrictive than the previous status quo since Iran did not actually have any plans to make nukes.

Obviously, the collapse of US soft power has been a boon to the entire world, and I think you can partially attribute that to Trump. But I think the far, far more significant factors are the inevitable failure of every US institution due to late capitalist instability and, most importantly, the rise of China as the soon-to-be dominant economic power (military power is another story, unfortunately).

You do make some good points I'm definitely thinking about, though.