Russiaxe2x80x99s military buildup along the border with Ukraine has clearly gotten the attention of policymakers from Kiev to Washington, D.C. CIA Director Bill Burns flew to Moscow to try to avert a crisis, while U.S. intelligence officials are reportedly warning NATO allies that a Russian invasion of large parts of Ukraine canxe2x80x99t be ruled out.

The possibility of Russian aggression against Ukraine would have huge consequences for European security. Perhaps even more concerning would be a Russian attack against a NATO member itself. Moscow might want to undermine security in the Baltic states or Poland, for instance, but could the Russian government successfully carry out a large-scale invasion of those countries? If recent wargames are any indication, then the answer is a resounding yes xe2x80x94 and it could do so pretty easily. In a 2016 War on the Rocks article, David A. Shlapak and Michael W. Johnson projected that the Russian army would overrun the Baltic states in three days.

Most of these wargames, such as RANDxe2x80x99s Baltic study, focus on fait accompli, an attack by the Russian government aimed at seizing terrain xe2x80x94 then quickly digging in. This creates a dilemma for NATO: launch a costly counter-attack and risk heavy casualties and possibly a nuclear crisis or accept a Russian fait accompli and undermine faith in the credibility of the alliance. Some analysts have argued that these seizures are much more likely to be small in size, limited to one or two towns. While that scenario should, of course, be studied, the concern about the feasibility of a fait accompli in the form of a major invasion still stands.

While the Russian army definitely has the combat power to achieve these scenarios, does Russia have the logistics force structure to support these operations? The short answer is not in the timelines envisioned by Western wargames. In an initial offensive xe2x80x94 depending on the fighting involved xe2x80x94 Russian forces might reach early objectives, but logistics would impose requirements for operational pauses. As a result, a large land grab is unrealistic as a fait accompli. The Russian army has the combat power to capture the objectives envisioned in a fait accompli scenario, but it does not have the logistic forces to do it in a single push without a logistical pause to reset its sustainment infrastructure. The Russian Aerospace Forces (with a sizable tactical bomber and attack aircraft force) and attack helicopters can also pick up fire support to alleviate artillery ammunition consumption.

NATO planners should develop plans focusing on exploiting Russian logistic challenges rather than trying to address the disparity in combat power. This involves drawing the Russian army deep into NATO territory and stretching Russian supply lines to the maximum while targeting logistics and transportation infrastructure such as trucks, railroad bridges, and pipelines. Committing to a decisive battle at the frontier would play directly into Russian hands, allowing a shorter supply to compensate for their logistic shortfalls.

Railroads and Russian Logistics Capabilities

Russian army logistics forces are not designed for a large-scale ground offensive far from their railroads. Inside maneuver units, Russian sustainment units are a size lower than their Western counterparts. Only brigades have an equivalent logistics capability, but itxe2x80x99s not an exact comparison. Russian formations have only three-quarters the number of combat vehicles as their U.S. counterparts but almost three times as much artillery. On paper (not all brigades have a full number of battalions), Russian brigades have two artillery battalions, a rocket battalion, and two air defense battalions per brigade as opposed to one artillery battalion and an attached air defense company per U.S. brigade. As a result of extra artillery and air defense battalions, the Russian logistics requirements are much larger than their U.S. counterparts.

Additionally, the Russian army doesnxe2x80x99t have sufficient sustainment brigades xe2x80x94 or material-technical support brigades, as they call them xe2x80x94 for each of their combined arms armies. A look into Military Balance, published by the International Institute for Strategic Studies, shows 10 material-technical support brigades supporting 11 combined arms armies, one tank army, and four army corps. Russiaxe2x80x99s Western and Southern Commands each have three armies and three material-technical support brigades to support them. In defensive operations, a Russian brigade can pull directly from the railhead. A trump card the Russians have are their 10 railroad brigades, which have no Western equivalents. They specialize in railroad security, construction, and repair, while rolling stock is provided by civilian state companies.

The reason Russia is unique in having railroad brigades is that logistically, Russian forces are tied to railroad from factory to army depot and to combined arms army and, where possible, to the division/brigade level. No other European nation uses railroads to the extent that the Russian army does. Part of the reason is that Russia is so vast xe2x80x94 over 6,000 miles from one end to the other. The rub is that Russian railroads are a wider gauge than the rest of Europe. Only former Soviet nations and Finland still use the Russian standard xe2x80x94 this includes the Baltic states. There are several railheads prior to Baltic capitals, but it will still take several days to reach and establish railhead operations. Forward railhead operations are more than just cross-loading cargo from train onto truck. It involves receiving and sorting cargo, repackaging for specific units, and storing excess on the ground. Due to the hazardous nature of military cargo, the ground needs to be prepared so that cargo can be stored in safe, distributed environments. This process can take one to three days. The site also needs to be outside the range of enemy artillery and secured from partisans. A single lucky shell or an rocket propelled grenade can result in a major explosion and have a disproportionate effect on the tempo of an entire division. This is assuming the key bridges, such as one at Narva on the Russian-Estonian border, arenxe2x80x99t destroyed and have to be repaired. Poland only has one wide gauge rail line, which runs from the Krakow region to Ukraine and canxe2x80x99t be used by Russian forces, without capturing Ukraine first. There are no wide gauge lines running from Belarus to Warsaw. Rail traffic moving across borders usually stops to cross-load cargo or uses adjustable railroad carriages and switches engines (which cannot adjust). In times of war, it is highly unlikely that the Russian army would capture enough Western train engines to support their army, forcing them to rely on trucks. This means that Russian army rail sustainment capability ends at the borders of the former Soviet Union. Trying to resupply the Russian army beyond the Russian gauge rail network would force them to rely mostly on their truck force until railroad troops could reconfigure/repair the railroad or build a new one.

Russiaxe2x80x99s truck logistic support, which would be crucial in an invasion of Eastern Europe, is limited by the number of trucks and range of operations. It is possible to calculate how far trucks can operate using simple beer math. Assuming the existing road network can support 45 mph speeds, a single truck can make three trips a day at up to a 45-mile range: One hours to load, one hour to drive to the supported unit, one hours to unload, and another hour to return to base. Repeating this cycle three times equals 12 hours total. The rest of the day is dedicated to truck maintenance, meals, refueling, weapons cleaning, and sleeping. Increase the distance to 90 miles, and the truck can make two trips daily. At 180 miles, the same truck is down to one trip a day. These assumptions wonxe2x80x99t work in rough terrain or where there is limited/damaged infrastructure. If an army has just enough trucks to sustain itself at a 45-mile distance, then at 90 miles, the throughput will be 33 percent lower. At 180 miles, it will be down by 66 percent. The further you push from supply dumps, the fewer supplies you can replace in a single day.

The Russian army does not have enough trucks to meet its logistic requirement more than 90 miles beyond supply dumps. To reach a 180-mile range, the Russian army would have to double truck allocation to 400 trucks for each of the material-technical support brigades. To gain familiarity with Russian logistic requirements and lift resources, a useful starting point is the Russian combined arms army. They all have different force structures, but on paper, each combined army is assigned a material-technical support brigade. Each material-technical support brigade has two truck battalions with a total of 150 general cargo trucks with 50 trailers and 260 specialized trucks per brigade. The Russian army makes heavy use of tube and rocket artillery fire, and rocket ammunition is very bulky. Although each army is different, there are usually 56 to 90 multiple launch rocket system launchers in an army. Replenishing each launcher takes up the entire bed of the truck. If the combined arms army fired a single volley, it would require 56 to 90 trucks just to replenish rocket ammunition. That is about a half of a dry cargo truck force in the material-technical support brigade just to replace one volley of rockets. There is also between six to nine tube artillery battalions, nine air defense artillery battalions, 12 mechanized and recon battalions, three to five tank battalions, mortars, anti-tank missiles, and small arms ammunition xe2x80x94 not to mention, food, engineering, medical supplies, and so on. Those requirements are harder to estimate, but the potential resupply requirements are substantial. The Russian army force needs a lot of trucks just for ammunition and dry cargo replenishment.

For fuel and water sustainment, each material-technical support brigade has a tactical pipeline battalion. These have lower throughput than their Western equivalents but can be emplaced within three to four days of occupying new terrain. Until then, fuel trucks are required for operational resupply. One might argue that the Russian army has the range to reach its objectives on their original tank of fuel, especially with auxiliary fuel drums they are designed to carry. That is not entirely correct. Tanks and armored vehicles burn through fuel when maneuvering in combat or just idling while stationary. This is the reason why the U.S. Army uses xe2x80x9cdays of supplyxe2x80x9d to plan fuel consumption, not range. If a Russian army operation lasts 36 to 72 hours as the RAND study estimates, then the Russian army would have to refuel at least once before tactical pipelines are established to support operations.

Sustaining Logistics Is the Hard Part

A Scenario in the Baltics

There are serious logistic challenges with large-scale fait accompli operations in the Baltics. Small scale fait accompli operations are feasible with small forces without a logistical challenge but on a large scale are far more challenging. Fait accompli requires Russian forces to overrun Baltic states and eliminate all resistance in less than 96 hours xe2x80x94 before NATOxe2x80x99s Very High Readiness Task Force can reinforce the defenders. This force wonxe2x80x99t stop a Russian attack, but it commits NATO to a land war, negating the very purpose of fait accompli.

Logistics are the key stumbling block in the fait accompli timeline. The railroad is wide gauge and usable, but the timeline is too short for captured railheads to be put back into operation. A dozen NATO air-launched cruise missiles fired over Germany can destroy key rail bridges at Narva, Pskov, and Velikie Lugi, shutting down rail traffic into the Baltics for days until those bridges are repaired. Logistic planners in Russian Western Command have to plan for a scenario in which Baltic states choose to fight a battle in their capital. Historically, urban combat consumes massive amounts of ammunition and takes months to conclude. During the two most prominent examples, the battles of Grozny in the Chechen wars and the Battle of Mosul in 2016, defenders tied down four to 10 times their numbers for up to four months. At Grozny, Russians were firing up to 4,000 shells a day xe2x80x94 thatxe2x80x99s 50 trucks a day.

Even in a Baltic scenario, Russian planners have to consider the risk that Poland, which can muster four divisions, will launch an immediate counter-attack, trying to catch the Russian army off-balance. The Russian army would have large forces tied to sieges of Tallinn and Riga while fending off a Polish counter-attack from the south. The ammunition consumption would be massive. During the 2008 Russo-Georgian War, some Russian forces expended an entire basic load of ammunition in 12 hours. Assuming the same rates, the Russians would have to replace substantial amounts of ammunition every 12 to 24 hours.

Herein lies the dilemma. Overwhelming local forces in the Baltics before NATO troops arrive does not give Russia time to establish railheads, forcing reliance on trucks. At 130 miles, they can only do one trip a day, generating a truck shortage. Russian planners could commit fewer maneuver forces and risk failing to overwhelm defenders. Alternatively, they could take a logistics pause for two to three days and give the Baltic states time to mobilize and NATOxe2x80x99s Very High Readiness Joint Task Force time to arrive. Meanwhile, they would be taking attrition from local partisans, NATO airstrikes, maintenance breakdowns, and loitering munition as seen in the latest Nagorno-Karabakh War. Either way, fait accompli fails, and conflict degenerates into protracted war, which Russia is likely to lose. Russian logistics can only support a large-scale fait accompli if NATO forces fight a decisive battle at the frontier. The bulk of supply consumption would take place close to Russian depots. Russian air forces can alleviate the logistic strain by taking on fire support. Whatxe2x80x99s uncertain is how long the Russian air force would provide close air support in the face of NATO airpower, given NATOxe2x80x99s ability to conduct standoff air-to-air engagements with long-range missiles from beyond the effective range of Russian air defense in Kaliningrad and St. Petersburg. A similar picture exists at sea. The combination of airpower, diesel submarines, and shore-based anti-ship missiles is likely to deny the Baltic Sea to surface fleets of both sides.

The Russian army has ample combat power to capture the Baltic states, but it wonxe2x80x99t be a rapid fait accompli unless the Russian government scales down the size of the territory it wishes to seize. Using Van Jacksonxe2x80x99s 2xc3x972 xe2x80x9cVariations of Fait Accomplixe2x80x9d diagram as a conceptual framework, we can fully appreciate the Russian dilemma. The logistic forces can only support a gradual fait accompli, which wonxe2x80x99t shatter NATO unity, instead giving NATO time to mobilize and seal off the land grab. Even if NATO chooses not to reconquer the territory right away, its member states would likely impose crippling economic sanctions until Russia caves in. On the other hand, the decisive fait accompli, such as the conquest of a full member state, may achieve the objective of shattering NATO unity, but it canxe2x80x99t be logistically supported by the Russian army. It also runs a major risk of miscalculation by assuming that all thirty member states have to declare NATO Article 5. On paper, thatxe2x80x99s true, but in practice, only the United States (to provide combat power), Germany, and Poland (to secure access) have to honor Article 5, and Russia would find itself in a major conflict that can escalate beyond the nuclear threshold.

A Polish Scenario

The Russian armyxe2x80x99s logistic challenges are different in a Polish scenario. There are fewer time constraints but greater difficulties due to the distances involved and lack of wide gauge railroads, which end at the Belarusian border. The closest railhead to Poland is Grodno and Brest in Belarus. The first is located 130 miles and the second 177 miles from Warsaw. For an army that is stretched to sustain 90 miles, that is a long supply line to support.

Kaliningrad could be considered as another option, but it is not practical, as it is landlocked by NATO members. The combination of NATO airpower, naval forces, and Polish land-based anti-ship missiles make resupply by sea unlikely. According to Military Balance, there is a Russian corps with major depots but no supporting logistics units to push supplies out. Maneuver forces would have to pull these supplies using organic logistic formations, a range of about 45 miles. The garrison there can hold out in isolation for a long time but cannot conduct ground offensive operations. The Russian army will be able to reach Warsaw but cannot capture it without a logistic pause to halt, reconfigure/repair the railroad, and build tactical pipelines and frontline depots. Instead of pausing for a couple of days as in the Baltic scenario, the pause in the Polish scenario could take up to a couple of weeks. This gives NATO breathing space to build combat power.

The logistics are also useful to assess a Ukrainian conflict as Russian forces are again massing on the border. The best means of interpreting the seriousness of Russian intentions is to track the buildup of logistic forces and supply dumps rather than count battalion tactical groups that have moved to the border. The size and scale of logistic preparation tell us exactly how far and deep is Russian army planning to go.

Russian Strategic Reserves

Russia could reinforce its Western Joint Strategic Command (Western Military district) from other parts of the country to increase logistic power, but not by much. As Michael Kofman has pointed out, NATO has the ability to horizontally escalate the conflict by holding most Russian theaters at risk. The Russian General Staff cannot ignore this threat. As a result, Russiaxe2x80x99s Central Command and parts of the Eastern Command are the only joint commands not facing an external threat and are able to reinforce Western Command. However, the sustainment forces they provide would be consumed by the additional combat forces that come with it. There are no extra trucks in the Russian army that are not tied to supporting engaged forces.

One of the strengths of the Russian army in a war in the Baltics or Poland would be its ability to mobilize reservists and civilian trucks. Russia still has a massive mobilization capacity built into its national economy, a legacy of World War II and the Cold War. However, mobilizing civilians to fight a war has major economic and political costs. To maintain political stability at home, the Russian people would have to genuinely believe they are defending their country. They will not tolerate husbands, sons, and fathers going off to a war on Putinxe2x80x99s whim. The last time the Russian government heavily relied on conscripts and reservists was during the First Chechen War (1994xe2x80x931996). Within two months, a major antiwar movement appeared, spearheaded by soldiersxe2x80x99 mothers.

Russia and the Fait Accompli

The Russian army will be hard-pressed to conduct a ground offensive of more than 90 miles beyond the borders of the former Soviet Union without a logistics pause. For NATO, it means it can worry less about a major Russian invasion of the Baltic states or Poland and a greater focus on exploiting Russian logistic challenges by drawing Russian forces further away from their supply depots and targeting chokepoints in the Russian logistic infrastructure and logistic force in general. It also means that Russia is more likely to seize small parts of enemy territory under its logistically sustainable range of 90 miles rather than a major invasion as part of a fait accompli strategy.

From the Russian perspective, it does not appear that they are building their logistic forces with fait accompli or blitzkrieg across Poland in mind. Instead, the Russian government has built an ideal army for their strategy of xe2x80x9cActive Defense.xe2x80x9d The Russian government has built armed forces highly capable of fighting on home soil or near its frontier and striking deep with long-range fires. However, they are not capable of a sustained ground offensive far beyond Russian railroads without a major logistical halt or a massive mobilization of reserves.

Deciphering Russiaxe2x80x99s intentions right now is increasingly difficult. Its military buildup on the border with Ukraine could be preparation for an invasion or it could be yet another round of coercive diplomacy. Nevertheless, thinking through Russiaxe2x80x99s military logistics capabilities could give NATO some insights into what Moscow might be planning to do next xe2x80x94 and what the Western alliance might do to protect its interests.

Lt. Col. Alex Vershinin commissioned as a second lieutenant, branched armor, in 2002. He has 10 years of frontline experience in Korea, Iraq, and Afghanistan, including four combat tours. Since 2014, he has worked as a modeling and simulations officer in concept development and experimentation field for NATO and the U.S. Army, including a tour at the U.S. Army Sustainment Battle Lab, where he led the experimentation scenario team.

Correction: A previous version of this article stated that Russiaxe2x80x99s Western and Southern Commands each have three armies and only two material-technical support brigades to support them. In fact, those districts have three material-technical support brigades.

Image: Russian Ministry of Defence