The last two years of fighting in Ukraine have humbled the overly confident and shown that, without countermeasures and with optimal flying conditions, an attack drone can disable any tanks through a shaped charge, top-attack, or mobility kill, including the Leopard II, M1 Abrams, or Challenger II, and even armored helicopters. However, assessing a weapon’s ability to inflict losses does not have the same effect as shifting warfare to defense dominance and the attendant requirement of attrition to achieve victory. Once the net effect of drones and their countermeasures, as well as precision artillery and anti-tank missiles, are accounted for, tanks remain the most powerful single combat system on the battlefield. Eventually, the Ukrainians should be able to resume concentrated offensive armored attacks.

Thoughtful tactical and operational analyses from the U.S. Army, the Marine Corps intellectuals, U.S. Special Forces members, CSIS, IISS, and the Institute for the Study of War all agree (with some variations) that drones are having a transformational impact on the war, especially on the attacker. The offensive is required for eventual victory, and the Ukrainians are in serious need of retraining if they are to apply the necessary combined arms tactics for any phase of the war. These analyses mostly reflect on the failure of the NATO-trained and equipped Ukrainian army in its summer 2023 attempt to conduct an armored offensive to the Sea of Azov. Due to deep Russian defense and flexible reserves, Ukraine could never achieve the concentration of force necessary to realize a breakthrough. Fortunately, Ukraine’s deliberate control over its operations ensured that losses were moderate and reflected a normal exchange rate of attrition. 

An IISS analysis argued that this was because Western-trained troops lacked the combat experience to be effective, whereas Ukrainian combat veterans, who were better trained for positional battle, could not master combined arms. However, given NATO’s successful experience with the 1991 Gulf War and the 2003 Iraq invasion, which were time-table rather than recon-pull operations, Ukrainian troops may have been trained for a deliberate attack rather than for genuine command decentralized needed for swiftly moving armor. Subsequent Russian offensives around Avdiivka, starting in October 2023, suffered similar challenges caused by the new technical problems of suppressing enemy drones and artillery.

The German general Heinz Guderian argued, in his seminal 1938 work on modern armored warfare Achtung! Panzer that successful offensive tank operations have four necessary conditions: attacks must occur on favorable terrain, with an element of surprise, with concentrations in mass, and be integrated into a combined arms force. 

The credibility of Guderian’s analysis in Achtung! Panzer, above other early writers, is established by the unprecedented accuracy of his predictions of the effects of armored warfare during the Second World War and the transparency of the explanatory variables in his model. While Soviet tank theorists generated similar insights, in practice, according to Air University Professor Charles T. Kamps, their Cold War doctrines were overly dependent on tempo while neglecting reconnaissance and overwatch. They thus would have suffered heavy personnel and equipment losses.

Guderian’s central problem is not achieving a break-in, which is addressed brilliantly in Erwin Rommel’s 1937 Infantry Attacks, but in how to carry that through into a breakthrough of the enemy’s lines and break out into the enemy’s rear to capture their supplies, artillery, and headquarters. In a series of vignettes in France, Romania, and Italy, Rommel demonstrates the importance of reconnaissance to exploit geographic opportunities, prompt and careful maneuver, the criticality of entrenchments, and machine-gun, infantry, and artillery combined arms in enabling a military advance against an adversary. 

In contrast, Guderian, who unsurprisingly worked in signals for the entirety of the First World War, repeatedly emphasizes the fundamental difference between the use of the tank for tactical versus operational advantages. Guderian concedes that armored vehicles add significantly to the infantry’s ability to destroy fixed targets and continue their advance. Guderian even made the then-controversial statement that the best tank killer was another tank despite the dramatically lower cost of anti-tank guns and rockets. It is no surprise, from his perspective, that the inexpensive and turretless Sturmgeschütz III Ausf. G tank destroyer, always used in penny packets, destroyed more Allied tanks during the war than the Panther and Tiger kills combined. However, its impact was an order of magnitude less than the use of tanks for breakthrough operations. 

Guderian stressed the inherent vulnerability of all tanks, both past and future, because of the poor visibility from a tank of anti-tank threats and their dependence on constant maintenance. Despite the periodic panic that easily hidden anti-tank guns, cheap infantry rocketed shaped-charges, long-range anti-tank missiles in the 1973 Arab-Israeli War, sophisticated mines, attack helicopters, laser-guided artillery projectiles, and today drones had superseded the tank itself, Guderian shows convincingly that the most lethal environment for tanks was the combination of ditches and artillery repurposed for direct fire during the First World War. 

In a series of exhaustive case studies of tank operations (Berry-au-Bac in April 1917, Messines in June 1917, Chemin-des-Dames in October 1917, Cambrai in November 1917, Soissons in June 1918, Amiens in August 1918), Guderian demonstrated the hugely disproportionate benefits of an operational breakout into the enemy’s rear over the tactical use of the same armored force to support the infantry in the attack, even when operational use initially inflicted most of the tank losses on the attacker.

Guderian’s emphasis on mass attacks was not simply the standard re-statement of the benefits of the concentration of force at the weak point modeled by the Lanchester square law formula of an inverse hyperbolic tan difference in losses. Rather, mass in an armored breakthrough was for the concurrent and simpler arithmetic purpose of overwhelming anti-tank defenses. The difference is that Lanchester calculates an exchange rate in fires, whereas Guderian’s mass is also about maneuvering past threats. Anti-tank systems are almost always more cost-effective than the tanks they kill, even when deployed in clusters. Still, they have a limited time during which to inflict attrition on an attacker attempting a breakthrough. 

Guderian’s emphasis on surprise does not primarily mean deception of the enemy. Tanks are intended to exploit fleetingly emerging opportunities detected by reconnaissance, which the attackers do not know beforehand. His requirement of operating tanks on favorable terrain can be traded off to increase surprise, as it was for Case Yellow and the Manstein Plan to invade France through the rugged Ardennes in May of 1944. Importantly, there is also a great difference between tank warfare in theory and the challenge of its managerial application in the friction of combat, both of which Ukraine would need to master.

The scale of the use of guided munitions, including cruise and ballistic missiles, and uncrewed aerial vehicles (UAVs), such as drones, far exceeds either the V-1 and V-2 attacks (over 15,000) of the Second World War, the high anti-tank missile expenditure of the October 1973 Arab-Israeli War, or the ballistic missile urban bombardments of the Iran-Iraq War (estimated at 750-900). According to the Ukrainian government, Russia has launched an unprecedented 43,000 guided projectiles and unguided missiles against Ukraine since the start of the war in February 2022. 

Russian drone attacks against Ukrainian infantry entrenchments (and vice versa) are constant and have superseded the interdiction effects of harassment fire by artillery. One RUSI estimate suggests that Ukraine is expending 10,000 drones per month. In contrast, Russia’s drone attacks are expected to rise from 250 daily attacks in May (equivalent to 7,500 per month) to 400-500 (15,000 monthly), mostly of the $350 per unit FPV (First Person) type. Similar trends are evident in the 25,000 drones used by rebels against the Myanmar government in October and November 2023 as part of their successful resistance.

The principal direct combat effect of attack drones in an environment of drone countermeasures is attritional. Drones have damaged tanks sufficiently to compel the crew to abandon the vehicle. However, drones must often be used in swarms to disable a target, estimated at six to ten versus armored vehicles (versus three to four per individual soldier), and the damage is often repairable. Drones are also used to inflict additional damage on already immobilized vehicles or to immobilize vehicles to instigate crew abandonment or for later destruction by artillery, which seems to be the situation with the case of one M1 Abrams tank. 

There is no aggregated breakdown of losses attributed to drones, except for naval platforms. There are rough estimates for specific battles, such as the 35 percent of seventy-five Russian tanks being destroyed by drones during the battle of Avdiivka from October 2–30, 2023, another thirty-nine tanks by drone in November 2023, and one unverified claim by a NATO official that two-thirds of all Russian equipment losses up to April 2024 were due to drones. In June 2024, a Ukrainian combat medic reported that ninety percent of casualties in the battle of Chasiv Yar over the previous six months were due to FPV drones.