I draw inspiration from a question that was asked to me: "you predicted in January that Avdiivka would last for another 3 years (for a long time), what led to the fall and change in your assessments instead?"
It must be said that I do not deny the January analysis, which was based on the data I had at the time and on the type of war that was taking place, an incorrect assessment was revealed due to the change in some conditions of the war, which I am going to analyze and to expand:
1) The Russians sent an incredible amount of men and equipment. Probably more than anyone imagined. I also wonder, would this alone have guaranteed the conquest of Avdiivka if there had been no other factors? I answer no. The attack on Stepove and Sjeverne (i.e. on the flanks), if conducted in the same manner as in January, would not have had any effect, considering that the thaw would have made these areas even more difficult for Russian logistics.
2) I believe that a fundamental point is the Russian ability to adapt to the reality of the battlefield. They stopped (or rather, slowed down, continuing to exert constant pressure) with the disastrous mechanized attacks of January, and began to move in small groups of infantry, supported by a lot of artillery and a lot of aviation (fab), which especially in the city area contributed to the crumbling of the fortifications. The Russians identified a weak point in the water basin area, and began to push into this area, also helped by some Ukrainian errors especially in the southern sector.
3) The chapter of Ukrainian mistakes is a chapter that is very linked to that of Russian success. Still taking into account the disproportion of men and equipment, the lack of artillery, and the current absence of defenses against aviation, I believe that some errors in the approach and tactics at the local command level were decisive:
a) The Ukrainians were very good at defending on the flanks, while in the city areas, they substantially relied on the fortified front lines of 2014. Perhaps also an excess of confidence, or perhaps the lack of planning of the previous months (or years), but there was a substantial absence of a well-thought-out second line system and fast communication channels, perhaps with mobile units ready to cover the gaps. It should also be noted that the area had been mined very little, dedicating this activity more to the areas outside the city (the famous flanks) than to the internal parts. As if the confidence in the 2014 fortifications was such as to discourage the Russians themselves
b) The bad weather blinded the drones, demonstrating the dependence on their eyes, on the Ukrainian side, which evidently reduced the classic Recon part, in favor of the automatic one, guaranteed by the drones. However, the fog played some nasty tricks, causing the Russians to enter the city perimeter at least twice in the south and once in the north.
c)I Russians have used the sewer pipes to enter the area of Via Soborna, and also to circumvent the zenith in recent days. I wonder why these conduits were only known to the Russians, and why, if they were known to the Ukrainians, they were not mined or destroyed. This seems like a really big intelligence flaw on the Ukrainian side to me. This allowed the Russians to come out behind the fortified front lines and cut the communication between them and the rear guards.
d) Once these "breaks" in the front occurred, there was also some automatism and some excessive delay in trying to plug the leaks. The Russians, contemptuous of the human and resource costs, threw their numbers into these holes, and some delays, as in the case of the industrial zone and Via Soborna, were fundamental.
Once the Russians managed to enter the urban perimeter of the city, the fate of the battle was essentially sealed. Not only the numbers, but also the aviation and artillery, mean that at this moment the Russians have a decisive advantage, especially in urban warfare. An advantage that is more difficult to capitalize when we talk about open areas (see Stepove and Sjeverne).
Surely the defense of Avdiivka could have been better prepared, at least to try to reach spring and slow down Russian logistics with the mud. The Ukrainian mistakes are perhaps not even very serious and are typical of battlefields. The problem is that the limited artillery ammunition, and the current impotence against the Russian air force, mean that every slightest Ukrainian mistake is fatal.
Above all because the Russian army, which traditionally does not worry about losses, has also demonstrated (already this summer) a surprising ability to adapt, which it certainly did not show at the beginning of the war, learning at its own expense from the enormous mistakes of the beginning.
It is hoped that even these defeats will help the Ukrainians to learn the lesson and improve and adapt to the changing war. Avdiivka is a great tactical success for the Russians, who remove the Ukrainian artillery from Donetsk, but it has very low strategic importance compared to other fronts.
It is hoped that the Ukrainian awareness (which I seem to glimpse) of a new defensive strategy (which I was already talking about in November), and the ability to learn from mistakes, will be of help in the future, when the entry into service of the planes (delayed spring\summer) will certainly limit the role of the Russian air force, and when (we hope) the ammunition needed to implement good defensive tactics has arrived, which is the basis for future changes and prospects.