Russia's new strategy in Ukraine likely to fail

 ISW:

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We assess that the Russian military will struggle to amass a large and combat-capable force of mechanized units to operate in Donbas within the next few months. Russia will likely continue to throw badly damaged and partially reconstituted units piecemeal into offensive operations that make limited gains at great cost.[1] The Russians likely will make gains nevertheless and may either trap or wear down Ukrainian forces enough to secure much of Donetsk and Luhansk Oblasts, but it is at least equally likely that these Russian offensives will culminate before reaching their objectives, as similar Russian operations have done.

The US Department of Defense (DoD) reported on April 8 that the Russian armed forces have lost 15-20 percent of the “combat power” they had arrayed against Ukraine before the invasion.[2] This statement is somewhat (unintentionally) misleading because it uses the phrase “combat power” loosely. The US DoD statements about Russian “combat power” appear to refer to the percentage of troops mobilized for the invasion that are still in principle available for fighting—that is, that are still alive, not badly injured, and with their units. But “combat power” means much more than that. US Army doctrine defines combat power as “the total means of destructive, constructive, and information capabilities that a military unit or formation can apply at a given time.”[3] It identifies eight elements of combat power: “leadership, information, command and control, movement and maneuver, intelligence, fires, sustainment, and protection.”[4] This doctrinal definition obviously encompasses much more than the total number of troops physically present with units and is one of the keys to understanding why Russian forces have performed so poorly in this war despite their large numerical advantage. It is also the key to understanding the evolving next phase of the war.

US DoD statements that Russia retains 80-85 percent of its original mobilized combat power unintentionally exaggerate the Russian military’s current capabilities to fight. Such statements taken in isolation are inherently ambiguous, for one thing. They could mean that 80-85 percent of the Russian units originally mobilized to fight in Ukraine remain intact and ready for action while 15-20 percent have been destroyed. Were that the case, Russia would have tremendous remaining combat power to hurl against Ukraine. Or, they could mean that all the Russian units mobilized to invade Ukraine have each suffered 15-20 percent casualties, which would point to a greatly decreased Russian offensive capacity, as such casualty levels severely degrade the effectiveness of most military units. The reality, as DoD briefers and other evidence make clear, is more complicated, and paints a grim picture for Russian commanders contemplating renewing major offensive operations.

The dozens of Russian battalion tactical groups (BTGs) that retreated from around Kyiv likely possess combat power that is a fraction of what the numbers of units or total numbers of personnel with those units would suggest. Russian units that have fought in Ukraine have taken fearful damage.[5] As the US DoD official noted on April 8, “We've seen indications of some units that are literally, for all intents and purposes, eradicated. There's just nothing left of the BTG except a handful of troops, and maybe a small number of vehicles, and they're going to have to be reconstituted or reapplied to others. We've seen others that are, you know, down 30 percent manpower.”[6] Units with such levels of losses are combat ineffective—they have essentially zero combat power. A combination of anecdotal evidence and generalized statements such as these from US and other NATO defense officials indicates that most of the Russian forces withdrawn from the immediate environs of Kyiv likely fall into the category of units that will remain combat ineffective until they have been reconstituted.

Reconstituting these units to restore any notable fraction of their nominal power would take months. The Russian military would have to incorporate new soldiers bringing the units back up toward full strength and then allow those soldiers time to integrate into the units. It would also have to allow those units to conduct some unit training, because a unit is more than the sum of individual soldiers and vehicles. The combat power of a unit results in no small part from its ability to operate as a coherent whole rather than a group of individuals. It takes time even for well-trained professional soldiers to learn how to fight together, and Russian soldiers are far from well-trained. The unit would also have to replace lost and damaged vehicles and repair those that are reparable. The unit’s personnel would need time to regain their morale and will to fight, both badly damaged by the humiliation of defeat and the stress and emotional damage of the losses they suffered. These processes take a long time. They cannot be accomplished in a few weeks, let alone the few days the Russian command appears willing to grant. Russian forces withdrawn from around Kyiv and going back to fight in Donbas in the next few weeks, therefore, will not have been reconstituted. At best, they will have been patched up and filled out not with fresh soldiers but with soldiers drawn from other battered and demoralized units. A battalion’s worth of such troops will not have a battalion’s worth of combat power.

The Russian armed forces likely have few or no full-strength units in reserve to deploy to fight in Ukraine because of a flawed mobilization scheme that cannot be fixed in the course of a short war. The Russians did not deploy full regiments and brigades to invade Ukraine—with few exceptions as we have previously noted. They instead drew individual battalions from many different regiments and brigades across their entire force. We have identified elements of almost every single brigade or regiment in the Russian Army, Airborne Troops, and Naval Infantry involved in fighting in Ukraine already. The decision to form composite organizations drawn from individual battalions thrown together into ad hoc formations degraded the performance of those units, as we have discussed in earlier reports.[7] It has also committed the Russian military to replicating that mistake for the duration of this conflict, because there are likely few or no intact regiments or brigades remaining in the Russian Army, Airborne Forces, or Naval Infantry. The Russians have no choice but to continue throwing individual battalions together into ad hoc formations until they have rebuilt entire regiments and brigades, a process that will likely take years.
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There is much more. 

The morale of its remaining forces is poor which hinders its ability to reconstitute them into a cohesive operation.  Russia is also having trouble recruiting replacements for its combat losses.  The Europeans and the US are also providing more advanced weapons to Ukraine to deal with the Russian operations.

Russia's current strategy would have had a better chance of success if they had used it initially.  Now it may be too late.  Not only have they lost a significant number of troops, but they have also had huge equipment losses and Ukraine is getting better weapons to deal with the remaining Russian equipment.

Western military leaders see an opportunity to further degrade Russia's combat effectiveness and they are becoming more willing to help Ukraine do it.

See, also:

What Putin's new commander reveals about his strategy