https://www-fr-de.translate.goog/pol..._x_tr_pto=wapp
I think since long that Crimea is a red line that to overstep could trigger Putolf to react in just any way imaginbable. I woudl rule out nothing if Ukriane could be successful in retaking Crimea, or the Russians being at risk to lose Crimea in any other way (isolation and blockade).
Just today I read in a German newspaper that the US is currently building a network of sensors on the front lines and in the hinterland that will enable them and Kiev to detect any kind of local use of nuclear weapons in the war zone and identify the originator.