Sounds like a scenario for the USA to take its final bow and leave the world’s stage.
That is an interesting interpretation of what I wrote, that would seem to point in the opposite direction.
Already, America has been caught in the paradox that either we defend Israel with conventional means, or Israel defends itself with nuclear means. By defending itself in this way, the US would directly suffer, both with the cut off of Middle East oil, and with contamination dumped on Middle America.
And that is not the end of it. A “successful” medium sized nuclear war then opens the door to other ones, such as between India and Pakistan, India and China, China and Russia, North Korea and South Korea and Japan, and probably more than that. And no guarantees that nobody will throw some at us, either.
The bottom line is that many of the countries of the world are belligerent and irrational. Our choice is either to keep their spats small in scale, or let them grow until we are caught up in more world wars. Just going home and closing the door won’t work anymore.