This post is educated guesswork based on what we’ve seen of Ukriane fortifications, what bridges have been destroyed and where Ukraine is flexing vs holding firm, with a bit of Google Earth mixed in. I suggest bouncing between the maps and the text, because these place names mean absolutely nothing in isolation.
On the Izyum front in the Donbas, the Ukrainians are pulling back on the eastern flank and dropping behind the east-west running Siverskyi-Donets river. That’s going to give them a lot of protection all the way from Sloviansk to Sievierodonetsk, allowing Ukraine to focus forces at blunting the push from Izyum. Expect the remaining towns north of the river to gradually withdraw in a deliberate fighting retreat back to a secure river line defence. Ukriane will make Russia bleed to take each town. Most of the bridges have already been blown, with the remainder to be destroyed once the final defenders are over.
To the far east, Ukraine is fighting extremely hard for the suburbs of Rubizhne and Popasna. These are key points that they need to hold, so there isn’t a gradual retreat strategy being employed here. Fighting in these urban areas has been heavy and not much ground has changed hands in recent weeks. I’m not seeing any signs of concern on this front, if anything the Ukrainians are securing a very intimidating defensive position. It’s almost like this is their home and they know what they are doing…
Towards the west, I expect the final defensive line to be along the railway line heading west from Sloviansk. There’s a heap of large towns all along that path, which would make very defensible positions. Artillery will be scattered south of that line, hitting any Russian advance before it reaches an urban area. The land north of that railway line will be very strongly fortified, as Ukraine knows this is where Russia needs a breakthrough to win.
Up north around Kharkiv, there’s been a big win to push 40 km east of the city. This is a very defensible town for the Ukrainians because it’s up against the very wide north-south river. The bridge there has been destroyed earlier in the war, so Russia would have had to withdraw to the north to keep a line of retreat open. Reducing Russian artillery bombardment of Kharkiv is nice, but in a military sense is the minor win here. Critically this gives the Ukrainian’s a safe launching point for further counterattacks into the east, which will put the Russian supply routes to the Iziyum front under dire threat.
Things to watch over the coming days is for a collapse in any of those critical lines that the Ukrainians are falling back to. Small losses in the flex territory is fine, losing that river or railway will be a massive blow. Likewise, if Russia gets a win pushing in from the eastern flank, it would make things very dangerous. If Ukraine can hold these points and attrit the Russian forces over the coming weeks, then a push from Kharkiv could be of enormous impact to the result of the war.