During the early days of the Russian invasion of Ukraine, it quickly became apparent that the Russians’ ability to supply their advancing forces was severely lacking. Even without the benefit of hindsight, this failure was not entirely surprising. Indeed, War on the Rocks published a piece shortly before the war by Alex Vershinin, a modeling and simulations officer for the US Army, pointing out the major logistical shortcomings of the Russian military. But this raises an important question: if Russian forces faced such significant logistical shortcomings that even American officials could spot them, why on earth did they attempt such a massive and highly taxing invasion?
No doubt part of the problem was simply the corruption and shoddy maintenance standards, such as the fitting of rotted tires and other defective components to vehicles and equipment, that plagued Russian forces. The sheer level of negligence was probably not fully appreciated by planners, leading them to underestimate the sustainment burden they would be facing. But this should not have been enough to lead entire axes of advance to completely freeze up. So where did things go so badly wrong? Obviously a full answer to this question will only emerge in the years after the war, when higher fidelity information is available to researchers. But it appears that hubristic planning assumptions directly contributed to an underestimation of logistical requirements. Thus, when Ukrainian forces refused to roll over, Russia’s maneuver formations quickly found themselves starving for food and materiel.
Before getting into the modeling, it is worth briefly dissecting Russian logistical doctrine in comparison to the United States. Unlike Washington, Moscow does not regularly plan for, or engage in, large scale overseas operations. Although it has undertaken limited overseas deployments, including contributing a fairly sizeable contingent to Syria in support of the Assad regime, Russian forces are simply not designed for power projection. Thus, those looking to analogize from the US military are bound to be led astray. Over 100,000 American forces are permanently deployed overseas; US ground forces were, until recently, engaged in multiple, simultaneous operations in the Middle East; and American warships maintain a constant presence across all of the world’s oceans. No other country even comes close to this level of global footprint, certainly not the Russians.
Consequently, Russia’s force structure is not designed to enable or support large overseas deployments. In fact, even sustaining moderate force levels in the relatively nearby countries of Central Europe would completely break Russia’s strategic logistics capacity. This is because Russia lacks the requisite air- and sealift assets to make advances at this distance sustainable. Where Russia does excel is in rail-based logistics, which is the primary means by which it supplies its forces. Russia’s rail network is well-developed and optimized to support defensive operations within its own territory. Moreover, Russia’s military has special rail troops whose role is both to protect domestic rail infrastructure and to quickly lay new rail to support Russian advances in other countries. The reason the laying of new rail is particularly important for Russian forces is that Russian rolling stock is designed for the wider gauge lines that exist within Russia. This makes it incompatible with rail infrastructure outside the former Soviet Union and Finland, necessitating the creation of new lines if rail logistics is to be employed to sustain expeditionary operations.
But none of this should have really mattered in the context of the 2022 Russian invasion of Ukraine. After all, Ukraine is proximate to Russia and easily within range of Russia’s strategic logistics assets. Moreover, Ukraine utilizes the same railway gauges as the Russians, obviating the barriers to rail logistics that would exist for Russian forces in most other European countries. Once Russia established a foothold at key railheads and secured the important, strategically-located airports, in other words, logistics should have been relatively straightforward. But there is one catch: until these key transportation nodes were secured, the initial invasion force would largely need to be sustained by trucks, and this is where the root of the problem lies.
In contrast to the US, Russian logistical formations tend to be smaller at every level, although there are of course exceptions. Whereas an American division doctrinally is supported by an entire logistics brigade, Russian divisions are only allocated a logistics battalion. Similarly, while an American battalion is supported by a logistics company, a Russian BTG has only a single logistics platoon. Material technical support (MTO) brigades represent the major logistical units assigned to Russian military districts. The brigade is comprised of two MTO battalions, each with 408 transport vehicles. These are the vehicles that transport supplies from central logistics hubs to the front. On average, each truck within the MTO battalion can carry 4.58 tons, meaning that each battalion can carry 1,870 short tons of cargo. As noted, these formations are generally allocated at the military district level, although Russian airborne (VDV) formations have MTO battalions that are organic at the level of the division. The allocation of MTO brigades is not standardized, so military districts possess different numbers of logistics units depending on their particular requirements and the likelihood that they will undertake expeditionary operations.
Unfortunately for the Russian military, even the most logistically well-endowed military districts lack the necessary capacity to support high-intensity combat operations via trucks alone. Importantly, however, they likely do possess the ability to sustain fairly deep advances against weak adversaries. This seems to be the root of the problems faced by Russian commanders: they optimistically envisaged a short, easy campaign lasting no more than a week or two, after which Ukrainian rail and airport infrastructure would be secured and available for use as a supplement to ground-based logistics. Moreover, because Ukrainian resistance was expected to be light in most areas, Russian commanders could plan to expend relatively few artillery rounds while limiting the main bulk of their advance to ad hoc formations of BTGs rather than entire combined arms armies. Indeed, this is exactly what we witnessed in the early days of the invasion. There was relatively little use of tactical level fires and a near total absence of combined arms operations in favor of small, unsupported columns advancing along a huge number of axes. Put simply, it wasn’t that the Russians did not understand their logistical issues. Rather, they simply did not expect the conflict to be sufficiently long or intense for potential logistical logjams to emerge.
But just how big of a difference does a tweak to these planning assumptions make? Well, to answer this question one need simply employ a basic logistics model and tweak the parameter assumptions. The most intuitive combat logistics model can be found in Joshua Epstein’s Strategy and Force Planning. For the purposes of this post, I employ a modified version of the Epstein logistics model developed by Ryan Baker to assess the maximum distance a formation can advance before encountering logistical deficits. This is expressed in the following equation:
The left-hand side of the equation is the maximum sustainable distance in kilometers. The right-hand side is a bit more complex but is, in fact, quite intuitive once you work through it. The “p” is simply the average payload per vehicle in the motorpool, while “c” is the average vehicle capacity actually utilized. This second term is important because most vehicles do not achieve their theoretical payload maximum due to volume constraints being reached before weight constraints are. “T” is the number of supply vehicles per maneuver formation (in this case, battalion tactical groups or BTGs). The alpha term is the attrition rate for supply vehicles, while “n” is the duration of the combat operation. The “a” represents the average availability of vehicles (in other words, the number excluding those down for maintenance), and “u” is the average daily operating time per vehicle. Finally, at least for the numerator, “v” indicates the average speed of the supply vehicles while “r” is the rate of advance of the combat unit.
The denominator contains just one variable, “k,” which is simply the amount of supplies consumed by the combat unit daily. The reason this is multiplied by 2 is that the distance is doubled by virtue of the fact that supply trucks must drive from the supply depot to the frontline and then back to the supply depot. Thus, one needs to discount the supply capacity per trip by a factor of two. As you can hopefully see, the equation is actually quite straightforward. It is simply the total amount of supplies and materiel that can be delivered per BTG, factoring in inefficiencies and attrition, divided by the amount of supplies consumed by the unit daily and the discount factor. By altering the values of some key variables, we can see just how significantly Russia’s overly optimistic planning assumptions distorted their projections of logistical requirements.
Because the exact number of MTO brigades allocated to the invasion is still a bit unclear, at least in the open source domain, I’ll simply use the units in the Western Military District as a stand-in. Obviously Russia’s invasion force was much larger, but what matters is the ratio of combat units to logistics units, and because the Western Military District has the best ratio of “tooth to tail,” it represents a conservative estimate.
As shown above, the Western Military District is comprised of three combined arms armies with MTO support: the 6th CAA, 20th CAA, and 1st Guards Tank Army. The armies collectively contain 12 regiments and 4 brigades of motor rifle or armored units. In practice, this distinction is not significant for our purposes, as doctrinally both regiments and brigades are supposed to be able to generate two BTGs. Thus, we should expect these formations to be able to generate 32 BTGs for combat operations. Of course, those of you accustomed to NATO military symbology will see that there are quite a few other units allocated to the Western Military District beyond motor rifles and armor. There is EW, mobile artillery, air defense, among many others. However, because the BTG is a composite formation that has artillery, air defense, and multiple other capabilities attached, I assume that these units largely just contributed forces directly to the BTGs rather than deploy as independent formations. Remember, the invasion was meant to be fast and light, so it seems unlikely that the full CAA would have deployed as part of the initial thrust. To supply these 32 BTGs, the three CAAs could collectively draw on 8 MTO battalions (although some of these are organized at brigade strength), meaning that each MTO battalion would have to cover four BTGs.
We now have most of the information we need. However, we must still must estimate consumption rates for each BTG. This is a bit tricky, but we can get fairly accurate estimates from open source reporting. According to the Washington Post, each Russian soldier requires around 440 pounds of food, ammunition, and fuel per day. A more conservative estimate, employing a universal estimation factor, is 485 pounds per soldier per day. But in fact this is also a bit understated, as traditional planning guidance (at least in the US) suggests multiplying this number by 1.1 in order to account for additional logistical strain created by civilians in occupied area who may rely on combat units for basic food and medical provisions until economic activity can be restored. With this multiplier incorporated, we must raise our estimates to 535 pounds per soldier per day. To generate a rough projection of daily consumption, therefore, we multiply 535 by the average number of soldiers in a BTG. Doctrinally, this number should be around 800, but evidence from the ongoing conflict suggests that, even in high readiness units, BTGs were often deploying with no more than 400-600 personnel. To be conservative, however, we will assign the average number of soldier per BTG to 700. This means that each BTG consumes 187.25 short tons per day.
The rest of the values are quite straightforward to estimate. The fraction of the payload utilized can conservatively be placed at 85% (for reference, during the Korean War this value was 88%). The number of trucks per BTG is simply the quotient of 408—the number of trucks in an MTO battalion—and 4—the number of BTGs for which each MTO battalion is responsible. The attrition rate can be set quite low. For reference, Operation Barbarossa saw attrition rates of .04% per day, so we can adopt that number as a conservative stand-in. The number of days is somewhat arbitrary, but I selected 21 to reflect the fact that the combat component of the special military operation was envisaged to be fairly short. Truck availability is conservatively set to 80%, which reflects German availability rates during Barbarossa (by contrast, in Desert Storm the Coalition had availability rates of around 85%). I also use Barbarossa to estimate values for average operating time, giving the Russians 12 hours per day, with the other 12 dedicated to maintenance and crew rest (this, again, is likely an underestimation, as Coalition forces managed 20 hours during Desert Storm). Finally, the driving speed of 45 kph is a conservative guess for heavy vehicles driving on degraded roads and muddy terrain, while 1.5 kph reflects combat forces’ average rate of advance during Operation Iraqi Freedom.
When one plugs even these fairly conservative values in, the maximum sustainable distance of advance is around 450 kilometers. Given that Russian forces were able to stage out of Crimea, western Russia, and Belarus, a sustainable range of 450 kilometers would easily have allowed them to reach every major population center in Ukraine, with at least 100 kilometers to spare. In short, logistical issues simply do not emerge as problems in this optimistic scenario, and this is not even crediting Russian forces with any rail or air logistics capacity. So, despite what many commentators allege, Russia likely did have enough logistical assets to support the special military operation, at least as long as the Ukrainians cooperated. But of course Kyiv was not planning on simply rolling over for the Russians, and this is where the problems began to emerge.
Perhaps the biggest issue initially was the intensity of combat operations. Within the first week, it became very apparent that a motley assortment of unsupported BTGs rolling down the highway would be unable to punch through Ukrainian defenses. Consequently, additional support units had to be deployed. Many of these units executed EW and air-defense missions to protect Russian convoys from drones and Ukrainian CAS platforms. But Russia was also forced to commit far more artillery to the fight, which massively expanded logistical pressure. Once one accounts for the expansion of Russian efforts to include additional units and much greater levels of artillery consumption, the full extent of the logistical burden becomes apparent. Using the 20th CAA as a benchmark, one finds that a typical Russian combined arms army, when fully deployed, would consume 4,350 tons of food and materiel every day. Just tweaking this one assumption reduces Russia’s power projection range to 228 kilometers, cutting the previous projections in half and moving several major Ukrainian population centers outside of Russian reach.
Of course, the other variables assumed different values as well. Under sustained attack from Ukrainian drones and bogged down around highway chokepoints, vehicles were forced to drive more slowly or even stop while burnt-out wrecks were cleared from the road. This, along with the invasion force’s inability to secure supply lines, pushed up attrition rates, with Russia, as of today, having lost the equivalent of 3.5 MTO brigades in supply trucks since the start of the conflict. And these growing attrition rates were made worse by the longer than expected duration of the conflict. Indeed, when one modifies the model values to account for these facts, one finds that sustainable advance distances fall to a mere 105 kilometers (just over 60 miles), which is not even remotely sufficient for the invasion of a country the size of Ukraine. Even if one gives Russian forces the benefit of the doubt and assumes that they operated their trucks 20 hours out of the day, as the US managed during Desert Storm, they could have still only sustained an advance out to 183 kilometers, which would be insufficient to reach Kiev.
Of course, as Russia’s offensive ground to a halt, its forces also largely failed to capture many of the air and rail facilities needed to enable larger scale logistical movements. Thus, failures compounded, with the MTO units’ inability to support the advance leading to ever greater pressures being placed on them. Russian maneuver formations lacked the supplies to sustain their efforts to secure the key railheads needed to relieve the pressure placed on supply trucks, and thus ever greater strain was placed on ground-based logistics.
These problems were further compounded by the way that Russia organizes logistics. Unlike NATO, which operates on a pull system in which units on the front constantly send back requests based on need, Russian logistics relies on a push system. In the Russian system, consumption rates are estimated by higher echelons according to a set of assumptions and are then pushed down to frontline troops at regular intervals. This is far easier to manage, as it makes provisioning more standardized and predictable. It has the disadvantage, however, of basing resourcing on assumed needs rather than actual needs. The result is that some frontline units may receive more fuel than they are able to store if they are advancing more slowly than predicted, while other frontline units experiencing heavier resistance than expected may be sent fewer rounds of ammunition than they require. The systematic underestimation of Ukrainian forces meant that, across the board, Russian combat units were insufficiently provisioned at the outset of hostilities, and this problem was only compounded by Russian leadership’s obsession with secrecy, which meant that logistics units were only briefed about the full invasion plans 24 hours before things kicked off. The result was a complete and utter fiasco. But, in contrast to what some analysts seem to be suggesting, this fiasco was not really the result of structural deficiencies in Russian logistics. Rather, it was the result of hubristic overconfidence leading decisionmakers to adopt absurd assumptions, thus setting their soldiers up to fail.