Thread by @ZimermanErik

I have often been showing some of the pre-war fortifications from the air in satellite images. Specifically also been talking about the good use of forests by UA forces in very stubborn defense. Near Lyman, by the village of Szczurowe and the (beautiful) blue lakes, we can take a

closer look of some of these forest defenses and fortification networks. These have been fully captured by Russia as they secured their control from #Lyman, a key railway hub, towards the Siverskyi donets river. From here they have moved in one direction across to Pryshyb

& Sydorove (which threatened the defense lines against the Izium front around Dolyna / Krasnopilya from the rear) and in the other towards Raihorodok against Slovyansk from the NE.

In general we must realize that the eastern front has been waged for months largely along the thick forest belt that runs from the NW to SE across eastern Ukraine. Whereas early on in the campaign UA forces defended only in towns & cities (and previously prepared fortifications),

UA forces evolved into being able to defend open territory in certain circumstances, especially in forests, which they have increasingly been using to infiltrate Russian lines and to fortify for defense. This forest belt largely runs along the Siverskyi Donets river & together,

along with important settlements along it, have been the main line of defense for #Ukraine from the Lugansk to Kharkhov. It has served them very well in slowing the RU advance, forcing RU forces to attempt narrow advances and river crossings, often with large losses. In the past

few weeks, we have seen what is perhaps the beginning of the end of this defensive line. Interestingly in the key encirclement of Lysychansk and Severodnetsk, the river line always held. It was the breakthrough from the southern urban & entrenchment line at Popasna that allowed

#Russian forces to advanced from the south all the way to the northern river front. There were no pincers, just one pincer. This made the advance for RU much more slowly, & contributed to the ability of UA forces to hold the salient for longer and then mostly escape. Ultimately

a predilection for tactical or PR success rather strategic, helped UA over-protect the river front and fail to stop the pincer from the south that rendered it mute. Discussed this June 29

https://twitter.com/ZimermanErik/status/1541983086371553281

and earlier June 22

https://twitter.com/ZimermanErik/status/1539644004383563777

Now the important issue of note is that RU is well passed the forest belt and river in many key places. It is also passed the pre-war fortified front in others and even has or is about to have rail supply lines beyond them. While UA

is better supplied with western artillery than it was in the past month or two, the pace of Russian advance, all things being equal should not be expected to necessarily be the same as through these territories ideally suited to defense. The wide forest belt west of Izium remains

of key strategic importance. If UA cannot hold it and no longer threatens the rail and road lines through Izyum, the rate of advance through the less defended and more sparsely populated areas may increase significantly. On the other hand RU is yet to pass the forest & river line

in several important sectors, largely from Izium up to Khakhov. But where it has in the south, UA faces imminent threats. The securing of the forest west of Izium, the capture of Siversk, and the collapse of the Dolyna front would put RU in this advantageous position.

It will leave the path wide open to the fall of Barvinkove, and with it the fall of the formidable Slovyansk Kramatorsk line, and thus the securing (or liberating as many Russians on both sides of the border would put it) of the rest of #Donetsk Oblast.

Key battles lie immediately ahead of us.

#UkraineRussianWar #RussiaUkraineWar