maybe in 11 to 15 years after eventual respective Democratic and a non-Trump Republican governments

And then the next trump comes in and reneges on all the agreements. Would take a few decades of stability as has been carefully constructed by the US since world war 2.

The problem with this is that there is now absolutely no reason for anyone to think that any treaty or other agreement made with any US administration (of either party) will remain in force after the next administration takes power.

Rebuilding any credibility internationally will require concerted effort by the legislative and judicial branches (and maybe states ratifying amendments) to rein in the currently out of control power of the executive.

This is still very optimistic. The only reason this would work is that America's negotiating partners want to believe the change is real. The American people will remain roughly the same electorate that elected Trump (for a second term, after he incited an insurrection), so the danger will remain.