> No other country would intervene with military force even if they did, because nobody wants a two-sided nuclear war.

That is a serious underestimation.

No, it's a fact. The West is not going to risk the Apocalypse for Ukraine. Unless Russia directly attacks a NATO country, there is practically nothing they can do to trigger a war between NATO and Russia.

I mean NATO is already involved with NATO countries supplying arms. The UK foreign secretary has even said that people have her full support if they want to go and fight for Ukraine (which is beyond irresponsible).

> if they want to go and fight for Ukraine (which is beyond irresponsible)

Why irresponsible? My take on it was that message was aimed at Ukrainians living in the UK who wanted to go and fight. Your average Brit isn't even going to humour that idea.

> The West is not going to risk the Apocalypse for Ukraine.

If Putin is launching nukes, it has nothing to do with Ukraine anymore. The choices are “do we let a madman play with nukes or not?" I think the answer is pretty obvious.

Could sanctions get bad enough for Russia to retaliate?

The next move will be a tactical nuke. Maybe targeting the black sea, any target not causing real casualties.

Just the radioactive fallout.

They can do a clean detonation if they detonate high enough in the atmosphere for the blast to not kick up and irradiate any dust. For a while now I've been convinced that a show of force like this is part of his plan in order to force a change in the calculus of his adversaries and get them on the back foot.