By Request

From comments:

Now that it looks like we may be on the short march to national self-immolation, there are questions that keeps nagging me.

Specifically, if it really hits the fan, how would other powers (read: Russia, China) work to turn it to their advantage? Related: If things REALLY got bad, and it looked like real nut jobs (with the ones I'm thinking about being hostile to Russia) were about to get control of the nukes, how would THAT play out?

The apocalyptic part of me is thinking that pre-emptive EMPs and depressed trajectory SLBM strikes on political and military centers of power could be in our future. That's probably just some anxious BS that could be cured by Xanax, but my mind keeps going there. If you have some thoughts on this, would you mind sharing them?

Others would tread very carefully. The scariest scenario for every nuclear power is when the theoretically rational actors lose control of their own nukes.

It's a scenario of real life baby-with-a-live-grenade - for everyone.
That's why continuity-of-government and continuity-of-command operational plans are some of the most thoroughly detailed, closely-held, and codeword classified far-beyond-top-secret war plans there are.

For the same reason no one tries to sneak up on a crazy guy with a gun, no one (sane) is going to try to "take advantage" of us or anyone if things go squirrelly. Everyone goes to full defensive posture, but nobody wants to get clever when the finger on the button may be some twitchy fruit loop.

We've been through it several times during Russian coups, and on our own for times like when Kennedy and Reagan were shot. The way it plays out in real life is probably akin to the scenes in The West Wing when the president was shot, or when the planes hit the WTC on 9/11: the word gets put out quickly and clearly through diplomatic channels
"Don't screw with us right now".
For this reason, I strongly suspect (from nowhere near the inner sanctum) that if it looked like the NCA (National Command Authority) ability to launch nukes was compromised or about to be, the depressed-trajectory SLBM coming at whoever was attempting a launch would probably be one of our own Tridents from an Ohio-class boomer.
Bet on it.

If you can think of the scenario, there's an envelope covering it sitting in a file folder in a secure safe at NORAD, or whatever passes for it nowadays.

As for EMPs, I defer to former USAF targeting guy and occasional commentor, RandyGC, who noted that EMP effects are largely theoretical, extrapolated from one above-ground test 60 or so years ago. The reality could be far worse, or it could turn out to be Y2K: a giant non-event.

Obviously, no one's going to test it out.

But it would do functionally nothing to the guys on subs and sitting in MCC launch centers, except piss them off, while not doing anything militarily useful except announcing you were willing to play Global Thermonuclear War instead of tic tac toe.

Ain't nobody sane gonna go there.

The insane (Norks, Iranians, random jihadi @$$tards, etc.) are a constant threat 24/7/365, so no point discussing that in this context.

As for national self-immolation, we're a hardy beast. The Nazis going full-on couldn't bring down the Soviet Union. I think we're at least that tough, even now. And an internal crisis would have to get stupid crazy out of hand to become a problem. (Not impossible, just rather unlikely, IMHO). I would expect varying levels of local and regional sportiness if things start to unwind, with some places being pestilential post-apocalyptic sh*tholes right now (Chicongo, Debtroit, D.C., etc.).

As Remus says, "Avoid crowds."

Our biggest problems tend to come from simple stuff no one was paying proper attention to: a squirrel commits seppuku via transformer, and 5 states lose their power grid; a Cat V hurricane lands right on the rinkiest section of levees athwart a major city; and so on.

Invest in planning in two ways: the likeliest scenario where you are, and the most catastrophic scenario where you are. For me here, it'd be The Big One monster earthquake, on both counts. Not, for instance, a meteor ending all life in one hemisphere, or the Yellowstone Caldera ripping loose and giving us two years of unending volcanic winter.
Or China trying to improve their hand by lobbing nukes into space to turn off our grid.

They're all possible, but until my funding approaches infinity, I'll worry about what's most likely. And with rare exceptions, most preps for the likely stuff will also work for most of the sci-nightmare stuff, unless nothing will.

If the horrendous happens, just bend over and kiss your ass goodbye.
Nobody gets out of this life alive, so you do the best you can with what you have.

If you're still concerned about it, the reference you want to consult is

this one.
Straight poop, on just about every aspect of what it'd take to get through (provided you don't live inside the CEP from a missile silo or other major military or industrial target).

Thanks for asking, and I hope that answers things for you, or at least gets you pointed in the right direction.