<THREAD>On Sunday, Putin ordered Russia's "deterrence forces" to be placed on "high combat alert." So far, the U.S. has not observed any change to Russia's nuclear force posture. What does this mean? (1/n) https://t.co/FihOe6JgRV

First off, the lack of change is a Good Thing! It doesn't alter the fact Putin made an explicit nuclear threat on Sunday, but it does dial down the aggressiveness somewhat. (2/n)

I had been expecting some observable change to Russia's nuclear force posture. Two Russian analysis I respect, @russianforces and @KomissarWhipla, suggested the changes would solely be to nuclear command and control.

They are right... so far. (3/n)
https://t.co/C8uInF399F

The problem for Putin is that, to extract concessions using nuclear threats, he needs to credibly threaten first use. Preparing nuclear command-and-control systems sends out a vague message of readiness for nuclear war, but isn't really much of first use threat. (4/n)

Perhaps Putin is fine with that. Perhaps his threat, as @BWallaceMP put it, is just "a battle of rhetoric."

But I'm not so sure. The Putin-is-a-bluffer theory hasn't worked out so well this year (and isn't one that @BWallaceMP has subscribed to before now). (5/n) https://t.co/Ke93GF5lyA

I don't think Russian nuclear use is imminent. But I wouldn't assume Putin has ruled it out. All his alternatives look bad right now. Basically, he can negotiate a cease first that respects Ukraine's sovereignty or continue the bloodbath of a conventional war. (6/n)

If he continues the war (as seems likely for now), things could look very bleak for him. @scharap put it well.

Putin's reported obsession with Gaddafi's death suggests he worries about the same fate. (7/n)

https://t.co/VUCMorkFgy

In these circumstances, nuclear use is a possibility IMO. I wouldn't be surprised if in the next days or weeks, absent some dramatic Russian victories, there are observable changes to Russia's nuclear force posture, possibly accompanied by more warnings. (8/n)

I have no sense whether strategic forces (threatening the United States) or nonstrategic forces (threatening Ukraine) or both would be alerted. (9/n)

Helpful observation from @russianforces about the possible nature of the alert. (10/n) https://t.co/1XDk43NPn1

Finally, as someone who has spent a lot of time thinking about unintentional escalation, I think deliberate escalation is more likely in this particular scenario because of NATO's noninvolvement. (11/n)

There's plenty of scope for accidents, but historically, isolated accidents don't tend to lead to escalation. Major misunderstanding are a much bigger problem, but are less likely in this situation than a truly desperate Putin, IMO. (12/12)