A lot of people are wondering what the deal is with the so-called "cauldrons" in which the Ukie forces seem to get surrounded over and over again. Are the Ukie generals simply stupid, or what is the deal? I will try to explain.
Remember that that Ukie forces are typically "heavy". They have lots of tanks, lots of artillery, lost of ammo, lots of soldiers, etc. At least initially. They are also much inferior in terms of tactical skills, morale and willpower. In contrast, the Resistance forces have dramatically fewer tanks, fewer artillery pieces, much less ammo and less soldiers too. But their morale is sky-high, their tactical skills excellent and they are fighting on their own land - a big "home turf" advantage. Add to all this the following: the Ukies are desperately trying to prove to the world that they are "winning" whereas the Resistance is trying to eject an occupying force. Now if you keep all that in mind, you will very easily understand how these "cauldrons" form. It typically goes like this:
The political powers in Kiev order the commanders of the so-called "anti-terrorist operation" to show some results. The latter get together and define what they consider a number of key towns and villages. They then order their forces to go in and take these towns/villages. The junta forces move in and with much superior firepower typically destroy a few Resistance roadblocks on the main roads and move to seize the said towns. At this point they report "mission accomplished - our flag is on the administration of town X". The BBC picks up the info handed to them by the Ukies and the world learns of yet another Ukie victory. In the meantime, Ukie terror squads are brought in to smoke out any sympathizers of the Resistances in the occupied towns. As for the tanks, they are used to protect the Ukie force while their artillery is used long range to terrorize the population of the next town on the list.
Then everything goes down the tubes.
First, a big forces requires lots of petroleum, lubricants, ammo, supplies, food, etc. But the roads are under constant attack by Resistance forces. Next, the Novorussians slowly but inevitably bring in some artillery which begins ponding on the Ukie forces. Gradually, the bigger Ukie forces is forced to dig in while the Resistance take back full control of the main roads and surrounding towns. That's it - the circle has closed, the Ukies are surrounded and a 'cauldron' has formed.
At that point two things happen: a) the Ukies try to retreat b) reinforcements are sent in to rescue them. But at this point the density and quality of Resistance forces is sufficient to block the main roads and to prevent both retreats or reinforcements. In some cases the Ukies succeed in breaking out or reinforcing, but typically at great costs in equipment and lives. And that brings me to another important point:
The Ukies prefer to fight on the main roads. The Resistance is at home in the forests, hills, fields and bushes (what the Russian military calls the "The Green"). That means that Ukie movements are very predictable. Not so for the Resistance. The Ukies fear the "Green" - the Novorussians love it. I don't know of a single battle so far in which the Ukies attempted to attack through, or from. the "Green". The Novorussians do that all the time.
Pretty soon, supplies become a real problem, and with more or less the entire Ukie Air Forces kaput, and the density of anti-air weapons of the Resistance, even large units go from a fighting mode to a survival mode. At least 4 Ukie death squads are in that mode right now, today.
But remember, the Ukies sill have more armor and more firepower, so it is not that easy to reduce and crush a cauldron - that is why the Resistance needs so much time to eventually finish them off. They do though, one by one. If they had the time and forces, they could do it easily, but they don't.
Right now, the main forces protecting Mariupol are all stuck in 2-3 cauldrons southeast of Donetsk. But instead of wasting time reducing them, the Novorussian Armed Forces have launched an attack along the sea coast towards Mariupol were the Ukies are already in a panic mode as nothing much stands between them and the Resistance. And this is the correct move for the Novorussians.
Just as in chess a blocked figure is essentially useless, so is a Ukie force in a cauldron. The important thing is to keep the initiative and press the advantage. This is why the Resistance is pushing towards Mariupol. If that city is taken, or even surrounded, or if the cauldrons south of Donetsk are reduced, that will mean a collapse of the entire southern front of the Ukie attack on Novorussia.
There are risks however. First, any Novorussian force moved in or towards Mariupol risks been cut off and surrounded by Ukie reinforcements. Now, I don't know for a fact what the Ukies are up to, but I bet you that there is total panic in Kiev and that reinforcements are sent from all over the country to prevent Mariupol from falling into Novorussian hands. The Novorussians need to keep a very careful eye over their shoulder (but then, I am pretty sure that the many GRU eyes in space and on the ground are already doing that for them). Second, the surrounded Ukies can try to join forces and then either break out or attack towards the north. If they fail, they will probably either do what they have done in the past - run for their lives and abandon all their heavy equipment or fight to the last man. Either way is fine for the Novorussians.
I hope that the short (and somewhat simplified) explanation above explain, at least in general lines, why and how these "cauldrons" are constantly forming.
Cheers and kind regards,
The Saker