Can he do this?

[Mike 03]

2. Only if Trump creates a whole new doctrine for a U.S. response

to nuclear threats.

In your scenario, is a nuclear weapon actually detonated? Or is the threat enough to cause Trump to "surrender" the country?

I can't predict what Trump would do, but this would have happened under no previous president. I worry about many things, but TBH this scenario is not one of the things I'm worried about. But it's good to look at all the crazy things he might do from all angles.

Hardly a week has gone by since early 2022 that Putin has not implicitly threatened to use nuclear weapons against somebody.

You might want to read the book "Nuclear War" by Annie Jacobsen. It presents a scenario somewhat like you are proposing--an intentional nuclear strike against the U.S. by North Korea, how the U.S. would likely respond. This would all unfold in minutes.

It's not possible to "win" a nuclear conflict.