Not sure I see the point of his threat. If Russia attacks UK Gov’t officials, doesn't that invoke NATO response?
Article 5 is about attacks on the territory of a NATO country. Posturing and threats don't count. The people around Putin are trying to keep from going out a window. He's afraid of someone deposing him and then negotiating with the Ukrainians and the west. The more they look like loons spouting impossible things, the safer they are in the eyes of Putin. Medvedev is in a particularly difficult spot because he would be a leading candidate to pull off a coup since he was president for a while when Putin hit his term limit.
By all accounts Russia is moving mobile reserves from Kremenia to Bahkmut but they ALSO stripped the north to send units south. The attacks on the troop concentrations in Marioupul were units being stripped from Kremenia and sent to the south. NOT the reverse. Russia is reinforcing the south which is EXACTLY what it seems Ukraine wants them to do ..exactly as happened in Kherson. Prediction: Units in south will not break and run. They are the best commanded and leadership will matter. They never broke and ran in Kherson and I don't think they will there, not at first. Some estimates have the south with 150k soldiers. Russia will have a problem concentrating a reserve to reinforce defensive lines with armor but you can bet this will not be a cakewalk.
The reason the units did not break in Kremenia is because Russia put an elite VDV unit into Lyman and bleed the Ukrainian assault. They bled it dry while troops reinforced Kremenia. They punished the Ukrainian assault with a single VDV unit. Then when other units were dug in Kreminia and prepared the Lyman units RETREATED under fire- very very difficult to do. They NEVER broke. Trying to help you understand that Ukraine is not dealing with primitive, brutal disorganized nobodies. Time and time again Russia has taken a pretty good knock on the chin and not had units collapse. The collapse only happened once with stripped out units operating at 15-20% of staffing on Kharkiv front. That's it. Never happened again. ONE time. The Ukrainians know this so they are not rushing forward blindly. They are feinting, moving, feinting, hitting units in transition, using all the weapons available, using weather, using information. They don't do all of that because they expect Russian units to break they do all of these things to gain even the slightest edge, to encourage the idiots in the russian MOD to make yet another mistake. Russian forces only break when Russian commanders do something grossly stupid such as put mobiks on flanks in Bahkmut and then it is a few hundred meters lost or maybe a few KM or strip all the manpower out of a region to reinforce another region.
The question to ask yourself if you want to think like the Ukrainian high command. IS where do you want them to strip assets? then find out if they have stripped assets. What can you do to convince them to strip more? Everyone is talking about an attack south. The terrain is lovely for it. It will obviously cut logistics. Russian commanders there are the best. Ukrainian and Russian bloggers talk about it, storm shadows hit targets in the south. Himars hits every other day in the south. Mobile armor made a probe all the way back in March(when it was still snowing the north, LOL) , LOTS of talk about it. What happens? Russia has reinforced and continue to reinforce in that direction. They are now putting armor units on trucks and moving them around to keep them mobile. Ukraine will surely attack soon and it surely won't really be the south. That's my prediction. But they will leave the head russian commander thinking it will come to the south ....leave him thinking that until it is too late to reinforce other areas. He's an idiot and his loyalty to Putin and incompetence are Ukraines greatest assets so they will also NOT target him. They will look to get Colonels in the field in the south.
The 58th Combined Arms Army which is responsible for the south is based around Zaprishia oblast, but a lot of the units that were attached to it during the Kherson campaign have been detached and moved to the Donbas.
The Ukrainian offensive in Kharkhiv was very lightly supported. Most of the vehicles were Humvees with 50 caliber machine guns. Any significant resistance would have stopped them and the VDV unit did slow them down, but didn't stop them.
The Donbas is very difficult terrain to attack on the east-west axis. The fact that the Ukrainians have made the progress they have on the flanks around Bakhmut is notable. They are routing Russians out of very easy to defend terrain.
I do agree with you that it's unlikely Ukraine will launch the offensive where everyone expects. But there are only three spots to launch an offensive at this point: the southwest towards Melitopol, the Southeast towards Mariupol, or northern Luhansk. Northern Luhansk would be the most productive if successful, but the route to the Azoz is the longest.
Russia lost a lot of men and equipment this winter. In the spring they also committed some of the last of their veteran units to Bakhmut. Many of the veteran units have been rebuilt twice already. With their training system completely broken those units are getting green recruits who don't know which end of a rifle is the dangerous bit. The thinning ranks of veterans have had to try and get these people ready for combat.
Most of the volunteers are going into the veteran units, so they have a bit more motivation than mobiks, but they are very green. Even well trained troops can break in their first combat encounter. Green troops with no training are even worse.
We'll see how the Russians do hold up to the offensive. It may be a Ukrainian slog as they slowly grind their way to the Azoz, or the Russians may not be able to hold the front and it may collapse under the weight of the assault. Except for the Bakhmut area there have been reports of about 3-4 Russians per 100 meters in the first line of trenches. If true that's a very sparsely defended front. With the mobile forces that were supposed to back them up moved to Bakhmut, that leaves a defense that is big on fortifications and low on manpower. Unmanned defenses are not really defenses, they may slow down an assault, but won't stop it.