I think this would, in general, be a really bad idea. Kowtowing to nuclear threats would lead to a huge incentive for various countries to acquire nukes (both to make nuclear threats, and to defend against nuclear threats), and thus would increase proliferation (and nuclear risk) considerably. Of course, if you can figure out a way to get Russia to de-escalate, that would be great, though I doubt anyone here has any ability to influence that. Barring that, my sense is the best strategy for the US  right now is to continue to provide Ukraine with much assistance without engaging Russia directly.

Good question. I've noticed on Twitter that any calls for de-escalation usually get mocked as 'weak', 'appeasement', 'submitting to Russia', 'doing a Neville Chamberlain', and 'failing to understand deterrence and game theory'. 

What's needed, IMHO, are some new ways of framing de-escalation as 'strong', 'dominant', and 'decisive' rather than 'weak', 'submissive', and 'waffling'. 

This is basically a matter of empirical political psychology: what kind of framings actually work best to help political leaders save face and look formidable when doing de-escalation?

One possibility (not yet tested) is to invoke parental protective instincts, e.g. politicians should be able to say 'It's more important to me as a parent to protect my kids and your kids from nuclear armageddon, than to push some reckless proxy war on the other side of the world, just to submit to the interests of defense contractors and military interventionists who don't care about my kids, or yours'.

That's just one possible example. I don't know how it would poll. But without some kind of clever, psychologically compelling rhetoric like that, it's very hard to sell de-escalation as a viable political strategy.

The most obvious thing to me would be to produce some good analysis for why de-escalation is good, if that is the case.