Thread by @BrynnTannehill

I haven't posted a thread on Ukr@ine in a while, since Twitter has been de-boosting all of them, and frankly nothing much has changed since December-ish. But... things are afoot that are worth discussing. A 🧵1/n

Sonce December, Soledar fell, and ~75% of Bakhmut is in Russian hands. Attacks on Vuhledar, Torske, and Avdiivka have failed. The Russian winter offensive mostly failed. The only real debate is whether the defense of Bakhmut was worth it for UAF. 2/n theatlantic.com/ideas/archive/…

Some argue that it bled Russia dry of reserves and pinned down forces while UA prepared for a spring offensive (probably mid-May-ish). Others point out that UA committed some of their best forces and lost people they can't afford to. 3/n nbcnews.com/news/world/ukr…

Russia seems to have mostly exhausted its supply of precision munitions, and most of the attacks on UA are coming from cheap, slow, Iranian Shahed-131/136 drones. Both sides complain that they are running low on mortar and artillery ammunition. 4/n bloomberg.com/news/articles/…

None of this is new. Neither is the ISW's report that UA is operating on the left side of the Dnipro SE of Kherson: UA has been making raids and incursions there since November. The area taken is a roadless, uninhabited swamp. 5/n

While some speculate this is the beginning of a beach head, or a diversion in support of the spring offensive, it remains to be seen. We can take a look at Russian defenses via OSINT, as well as some of the known unknowns, and even speculate. 6/n

First, let's look at where we know Russia has been building defenses. From this we can infer what RU wants to defend most, and where they believe UA wants to strike. I'll look closely at 3 regions: Kherson, Zaporizhia, and Luhansk. (Credit to @bradyafr ) 7/n

In general (but not universally) RU isn't building fortifications around cities and towns. These are defensive barriers in and of themselves, and during the fall UA avoided assaults on defended urban areas, knowing them to be meat grinders that can stall an offensive. 8/n

In Kherson, RU has erected less fortifications. The river is a barrier to logistics, and a schwerpunkt here seems unlikely given this. Russia has erected defensive positions along the chokepoints between Kherson and Crimea and the roads to Melitopol, however. 9/n

The conclusion to draw is that Russia either doesn't really care too much if it loses its toe-hold in Kherson, doesn't think Ukraine can sustain an offensive through here, or both. Their main goal here is to prevent a re-taking of Crimea. 10/n

However, the North Crimea Canal, which supplies much of Crimea's water supply, is in this region. Taking it would complicate Russia's ability to sustain the peninsula somewhat. So, there is some incentive for UA in this region. 10/n

Next there Zaporizhia. Way back in December I speculated that a thrust towards Melitopol made the most sense for UA, and Russia seems to agree: RU has focused on building defenses here, and are often 3-5 layers thick. Going straight into the teeth of defenses is usually bad 11/n

What might make more sense here is an attempt to attack south from Vuhledar towards Maruipol. Retaking Mariupol, or at least surrounding it, would cut rail lines supporting RU troops. It would also allow holding the ports in Mariupol and Berdyansk under fire. 12/n

This would create a logistical nightmare for RU, cutting off both rail and seaport re-supply. It would also allow later offensives to bypass many of the defenses built this winter. How many red dots do you see between Mariupol and Berdyansk or Melitopol? 13/n

Next there's Luhansk, where defenses are thick, but also appear to be one deep. The area here is sparsely populated, meaning less towns to bog down in. Starobilsk is a major supply hub: taking it would create all sorts of logistical problems for RU in Northern Luhansk. 14/n

The logistics would make holding Severodonetsk and Lysychansk difficult, and would allow further offensives (Aug/Sep-ish) making a "left hook" to bypass the defenses erected along the current front lines in Luhansk and Donestk. 15/n

Here's my big take-aways from these maps:

* UA has some opportunities to create massive logistics problems for RU down the road.

* US has shown patience before with creating a logistical problem, and then waiting for it to come to fruition (Kherson) 16/n

* War is about creating conundrums for your adversary. Any of these three options creates a problem.

* Ukraine gets one shot at this: they need to pick whatever they think is most likely to work, and provide the most bang for the buck. 17/n

* For Russia, an attack towards Mariupol is the worst threat, followed by Starobilsk, followed by retaking of the Crimean Canal. The last is annoying but mitigable.

* The difficulty of each is the opposite: the canal probably the easiest, followed by Starobilsk, etc... 18/n

* UA doesn't have to win the war in one offensive: simply creating further untenable situations or impossible operational dilemmas for RU is sufficient

* UA MIGHT have the resources to try two at once. Kherson and Luhansk would make the most sense to split RU reserves. 19/n

* RU's use of blocking units 3-deep means that once you create a breach, and there's no one left to shoot people who are retreating, suggests that defenses could crumble quickly if UA secures a breach. 20/n

* I am dubious of RU's ability to quickly and effectively reassemble forces for a counter-attack. Training is bad, morale is bad, vehicles are in short supply / worn down, etc.

* Likely response would be to fall back to the next line of defenses far to the rear (a la Izyum) 21/n

* Ukraine's offensive likely has a built in culmination point based on ammunition and fuel / fuel trucks. We saw this happen in the Kharkiv / Luhansk offensive last year. UA needs to hit hard, move fast, and secure their primary objective(s) quickly. 22/n

* Western aid of tanks (or lack thereof) is going to complicate things a bit.

* Don't underestimate how good the Bradley is.

* This is probably an overestimate of how much UA has available, but it's a start. 23/n

* We don't know how much ammunition RU or UA has kept in reserve for this

* RU milbloggers are jumping at their shadows over every move UA makes

* The US has consistently underestimated UA capabilities, and over-estimated RU 24/n

* UA is not stupid. If the offensive fails, it could dramatically hurt their ability to retain vital western support. Whatever Course of Action (COA) they select, I believe that they will pick one they believe to have a near 100% chance of success. 25/n

* RU is spread thin enough, and UA has enough forces, that I believe UA will select a COA that is very likely to succeed, and will create the maximum ongoing operational dilemma possible for RU. However, without access to very specific intel, it is impossible to predict. 26/n