‘War is the mother of all inventions’ stated historian AJP Taylor in 1972. Whilst this remark upon the First World War would meet with perhaps some understandable opprobrium in 2024, the concept that innovation both renders obsolete some technology and shapes warfare is one borne out by twenty-first-century evaluation (War and Technology – Foreign Policy Research Institute (fpri.org)). As has been documented in our previous articles [1,2] the FPV drone, a weapon deployed in numbers which have surged since Russia’s full-scale invasion of Ukraine in February 2022, can arguably be seen as a weapon that has shaped aspects of warfare on the modern battlefield. Their application has been shaped by the operational needs of the combatants, with General Zaluzhny remarking on their value in December of 2023 [3].
The opening months of the Russian invasion of Ukraine in February 2022 saw concerns raised [4] about the obsolescence of certain weapon systems. At the beginning, Bayraktar TB2 drones were highly effective against Russian armoured columns, raising doubts about the utility of main battle tanks, but after their initial widespread impact, their perceived ascendency appeared to wane [5]. Nevertheless, it is now widely accepted that the tank remains a critical battlefield asset.
The FPV drone, which entered this war without the expectation of becoming a key asset for the two opposing sides has now garnered acclaim and interest across NATO countries for its application on the battlefield [3]. This weapon arrived without the type of publicity attached to other weapons systems, yet has since proved to have had a far greater significance on the battlefield than more expensive platforms, especially for the relatively cheap cost [6] but also for their scalability. This type of weapon was first created using basic components that were often homemade or sourced from China. However, since their inception, various organizations such as UNITED24, and volunteer groups like Wild Hornets, and Drony Nemesis have taken the initiative to produce thousands of high-quality drones using mostly locally sourced components. These weapon systems are usually easy to assemble, once the key components are fabricated, and do not require extremely long training courses. However, drone pilot schools have been established in Ukraine to train drone pilots.
FPV drones gained recognition on the battlefield during the spring of 2023, with their use rocketing during the summer of 2023. However, this weapons system had already started being used by late 2022, initially in an experimental campaign to validate indigenous designs [7]. Although not as ubiquitous as perceptions from social media may indicate, this phase of the Russo-Ukraine war has seen FPV deployment on the battlefield in a quantity and to an effect never before witnessed in warfare [6].
Analysis of FPV usage on positions
Our team has been studying this new weapon, recently focusing on its use against specific targets, with this analysis focusing on FPV strikes against positions. Positions refer to any physical obstacles that provide cover, such as foxholes, bunkers, trenches, buildings, and trees. While Ukrainian forces have recently intensified their strikes against these targets, the effectiveness of their capabilities is illustrated by the accompanying graph. Within two weeks, Ukrainian forces executed almost three times the number of strikes recorded in the previous period, with 154 strikes in two weeks. Similarly, Russian forces have almost matched their one-month record, tallying a total of 187 hits. This raises the question of which specific types of targets within this category were most likely to be hit.
Through the analysis of data related to strikes by FPV drones, we can better understand the extent of the threat. Andrew Perpetua and his team, with whom I have been working closely on this topic, have collected data on each strike’s video and used this data to classify each strike’s target. The data covers the period from November 2023 to February 2024 and is presented in the following pie chart showing the different types of positions targeted. Russian forces conducted over 757 strikes during this period, with trenches being the most frequently targeted position, accounting for a staggering 70.9% of the strikes. Civilian houses were the second most targeted position at 9.9%, followed by bunkers at 9.1%.
Trenches: a brief introduction
Before delving any deeper, let’s have a rapid overview of trenches and their development. Trench warfare appeared for the first time in the ancient ages during the Roman Empire when it was used mainly during sieges. However, it got more and more importance during World War I; a war which profoundly influenced military strategy and tactical doctrine. Intricate trench systems provided soldiers with protection from enemy indirect fire and also served as avenues for movement and communication on the battlefield. However, constructing effective trench systems required careful planning, engineering, and maintenance to maximize their defensive capabilities.
Trench systems were typically constructed in a zigzag pattern, with interconnected lines forming a network of defensive positions [8]. This design served multiple purposes: it minimised the risk of a single artillery strike wiping out an entire section of the trench, provided cover from enfilading fire, and allowed for expeditious movement of troops within the trench network. Moreover, the zigzag layout reduced the chances of a direct hit by enemy artillery shells, as the trajectory of incoming shells would often be deflected upon hitting the trench’s parapet.
Effective trench construction involves several key components. Firstly, the depth of the trench is critical. Trenches needed to be deep enough to provide adequate protection from enemy fire and shrapnel, yet shallow enough to avoid flooding during rainstorms. Drainage systems consisting of sumps were implemented to prevent water accumulation, aimed at providing more habitable conditions for soldiers. Furthermore, trenches were fortified with various materials to reinforce their structure and enhance protection. Sandbags were commonly used to bolster trench walls and provide additional cover for soldiers [8-9]. Revetments, made of wood or corrugated iron, were also employed to prevent walls from collapsing and to absorb the impact of artillery shells. Additionally, barbed wire entanglements were strategically placed in front of the trenches to impede enemy advances and channel their movement into kill zones.
Communication trenches, which connected the frontline trenches with the support and reserve lines, were essential for troop movement and logistical support. These trenches were constructed parallel to the frontline trenches and provided a safe passage for reinforcements, supplies, and wounded soldiers, minimising exposure to enemy fire. Maintaining trench systems was an ongoing challenge. Constant shelling and weather conditions posed significant threats to the integrity of the trenches. Soldiers were tasked with regular maintenance duties, including repairing damaged sections, reinforcing fortifications, and clearing debris. Additionally, sanitation measures were crucial to prevent the spread of disease in the unsanitary conditions of the trenches [8-9].
In Ukraine in 2024, the use of trench systems shows the importance they retain. However, the type of trench system described above has been rarely witnessed in this conflict, with types of entrenchment varying across the front line. Even the Russian lines in the south have been shown to have weaker points where their positions are less protected and developed as was highlighted by the breakthrough of the Verbone line, presented in the picture below from the CSIS. In general, Ukrainians have been shown to possess better positions with underground quarters and fortified firing positions [10]. However, it is also known that positions of this quality are by no means ubiquitous, [10] with most of the trenches subjected to frequent changes of hands [11], which results in infrequent trench maintenance from either side.
Some positions are noticeably better protected than others, with those less protected being more exposed to the threat of FPV strikes. Trenches that lack nets to protect or conceal personnel, as well as erosion or absence of embankments, can leave soldiers at a higher risk of FPV strikes. Other issues faced by infantry in Ukraine are similar to those faced by soldiers living in WWI trenches, with flooding and wall collapses requiring conventional prevention measures like floor elevation. Disruption of communication passages between different positions also exposes soldiers to enemy fire, such as that from snipers and mortars.
Current situation on the ground
Currently, we are examining the effectiveness of artillery barrages combined with precision strikes with FPV drones in combat zones. This strategy has been observed frequently within frontline combat zones, particularly in southern areas containing numerous trench systems and tree lines which run between settlements.
Using recent satellite imagery from Sentinel 2A, we overlaid our data to illustrate the impact of this strategy. The imagery showed an abundance of craters dotting the landscape around tree lines and trenches, indicating the areas affected by artillery barrages. As shown from the image, the use of FPV drones resulted in strikes within a discernible pattern of converging artillery craters, highlighting the precision of these particular attacks.
The analysis of this tactical integration reflects Russian doctrine against defensive positions and highlights the importance of a meticulous compilation of battlefield data. In this case, the strategic use of artillery disrupts enemy movement, forcing them to seek shelter in trenches. This sets the stage for accurate FPV strikes targeting infantry in manned positions once an artillery barrage subsides. In relation to artillery alone, this approach is not new and was widely used in World War I, where artillery barrages followed various patterns to hit infantry between different strikes. This strategy is known as “the dilemma of fires” and can be applied to both direct and indirect fires. In this case, it is done using direct strikes by FPV drone
According to our observations, Ukraine has adopted the strategy of using FPVs for precision strikes due to a lack of artillery rounds; it seems that they are generally not employing the aforementioned strategy of artillery shelling combined with FPV strikes. This can be evidenced by the following imagery, where we can see few discernable artillery marks in Russian-held territory. However, the use of FPVs is notably high in two areas which contain concrete buildings and trenches. It is worth noting that there have been intense attacks on the tree line across the fields below, suggesting the presence of Russian defensive positions that may not be visible in low-resolution imagery.
This second overlay shows a particular and interesting usage of FPV in a highly contested environment. This shows the effort of Ukrainian armed forces to contain the growing pressure from the north in the Stepove direction. The use of FPV drones here is very much a substitute for artillery and mortars. The Russians are likely using the thick tree lines along the railway to cover their movements. However, surveillance drones have been recorded actively guiding FPV drones to the target. A striking example of this disparity is seen by the railroad which separates the de facto frontline in this area. Ukrainian forces had previously held their positions in Stepove but were subjected to a large number of artillery strikes, and the town is now contested territory. Ukrainians, in lieu of the artillery support they require, have been using FPV strikes to halt the advance of the Russian forces.
Impact on current trench warfare
FPV drones, as the data above illustrates, have made trenches one of the most dangerous places to be at this moment in the Russo-Ukraine war, both tactically and psychologically, for soldiers.Trenches once considered a less dangerous place for infantry, have become increasingly perilous due to the proliferation of agile and fast FPV drones. We thus return to a question raised at the beginning of this article: is trench warfare obsolete?
As demonstrated above, the answer to this question is firmly in the negative. It is an unavoidable fact, however, that trench warfare is in a state of flux and resultant adaptation. To understand how it is changing and how it should change, it is necessary to explore the concept of Area Defense. Area defence is a strategy that leverages the strengths of a tightly coordinated defensive operation, allowing forces to consolidate, reorganise, and transition to other tactical operations such as offensive manoeuvres [12]. Subordinate units may be tasked with conducting area defence within their assigned areas as part of higher-echelon operations. Units opt for area defence when they are directed to defend or retain specific terrain, lack resources for a striking force, possess less mobility than the enemy, or when terrain features naturally limit enemy manoeuvrability.
The strategy is viable when there is sufficient time to organize defensive positions, terrain constraints hinder friendly air superiority, or when transitioning from offensive operations to stability tasks necessitates force preservation. In executing area defence, units combine static actions like fires from prepared positions with mobile tasks such as counterattacks and repositioning forces. Reserves and uncommitted forces are utilised for counterattacks and spoiling actions to disrupt enemy forces and prevent massing.
Organization of Forces for an Area Defense
An area defence strategy comprises three crucial components: the security force, the main body, and the reserve [12]. The security force is responsible for early warning and safeguarding vital assets, stationed ahead of main defensive positions along probable avenues of approach. Typically, manoeuvre battalions and Brigade Combat Teams (BCTs) conduct forward screen or guard operations, while higher echelons may deploy a forward covering force. Flank security forces are designated to cover any gaps that may emerge between units during defensive operations, ensuring comprehensive protection.
The main body of the defence focuses on retaining key terrain, utilising prepared positions and conducting counterattacks as necessary. The majority of combat power is concentrated in the main battle area (MBA), geared towards engaging and defeating attacking enemy forces [12].
Reserves are maintained in readiness, and primarily tasked with executing counterattacks based on pre-established plans. They may also be assigned roles such as restoring defensive integrity, blocking enemy penetrations, or seizing initiative opportunities. Defensive positions must be capable of achieving mission objectives independently or in combination. Units employ two methods for position placement in area defence: defence in depth and forward defence.
The type of defence is often associated with geographical characteristics and units may execute a variation of area defence strategy when in the presence of a linear obstacle, such as a mountain range, river, treelines, railtracks large exposed open fields etc. When operating with an extended line deploying forces along the entire length of the linear is challenging if possible. Conversely, a defence-in-depth approach acknowledges the possibility of enemy crossings at various points and aims to hinder rapid enemy exploitation while diffusing their combat power [12].
Now that we have examined area defence and we have covered what it means to man a defensive position, it is necessary to explore what we know about countermeasures against Unmanned Aerial Vehicles. A key point within current NATO doctrine is to increase the survivability of the units when a hostile UAV is detected. Survivability in simple terms refers to retaining the capabilities to operate while evading or enduring a hostile action and, when possible, avoiding detection, and effectively deceiving enemy forces [13]. It encompasses factors such as armour protection, mobility, tactical proficiency, and situational awareness. When addressing area defence, soldiers typically rely on two options: passive and active countermeasures against enemy UAVs. Ideally, both strategies should be employed synergistically. However, a significant challenge arises in the current scenario. Electronic warfare capabilities are often constrained, and access to anti-drone weaponry is limited due to the high cost [14], rendering active measures a rarity. This underscores a pressing need for a shift in approach. Nevertheless, implementing such changes may prove impractical given the expansive nature of the current defence lines within the conflict zone. Regardless of active measures, passive measures must always be employed. Passive approaches are aimed at reducing the risk of detection and targeting, and this is considered the first line of defence against UAVs. This class of measures includes camouflage, deception, dispersion, displacement and protective constructions. The latter are to be considered for shielding the units from detection, observation, and attack.
In the context of any defence strategy, camouflage and concealment are key components in increasing the difficulty faced by hostile reconnaissance assets in identifying targets. This can be influenced by factors such as unit proficiency, available time, environmental conditions, and the resources accessible to the unit. Furthermore, camouflage must consider the presence of sensors sensitive to various regions of the electromagnetic spectrum [13]. Camouflaging across different sensors within the electromagnetic spectrum poses challenges. Technical solutions to this problem, such as the European “Barracuda” or the US “ULCANS,” offer significant enhancements in concealment across the electromagnetic spectrum. However, these specialized tools are complex to procure and can only be used on high-end assets such as artillery howitzers, command and control centres, etc.
Nevertheless, even factors such as shapes, shadows, patterns, and texture can disrupt a unit’s ability to blend with the background, rendering them visible even in visible light to UAVs, thus making them vulnerable to artillery or, in many cases, FPV drones. Below are examples of trench lines, sufficiently deep to shield soldiers from fragmentation, yet entirely exposed to top-down attack. The location chosen for analysis is southwest of Robotyne; this trench system is held at the moment by the Ukrainian forces. Despite these trenches’ intricacies, even from satellite imagery, it is possible to observe the absence of any type of cover on the trenches themselves. This, unfortunately, has been even more visible in recent FPV videos released by Russians operating in this area.
Footage recorded of several different attacks on this position shows trenches in conditions offering inadequate protection, fortified areas visible to observation, and exposed trench lines. This is one of many cases where a simple surveillance drone can easily assess the strength and force composition within the trench, enabling targeted FPV precision strikes on the trench’s infantry and other assets.
Moreover, the shape and darker colours of the trench line not only make it far easier to spot and locate the trench but also to identify any soldiers or weapons within it, thus presenting targets of opportunity. In the next image, we show a sequence of an FPV attack on an underground position. Once again, the entrance is exposed, and the darker background is a conspicuous feature. Due to its manoeuvrability, the drone only needs to hover at the entrance and detonate. The explosion propagates throughout the bunker, as depicted in the second frame, where smoke emerges from another area of the trench system.
Conclusions
It is challenging for me, from the comfort of my office, to write the final part of this article because I raise several issues within that may not be the fault of specific commanders or leaders. Most of these issues are likely direct consequences of the intensity of this conflict and the lack of Western support, particularly in terms of electronic warfare, anti-drone technology, and trenching equipment.
However, the significance of the impact brought about by FPV drones on the battlefield cannot be ignored. Neither can the mistakes or the practices that in 2024 place the lives of defenders in even greater peril. FPV drones and their innovations have transformed trenches into extremely dangerous, and the most likely to be attacked by FPV drones.
We could conclude that trench warfare needs to change and improve in the following aspects:
- Having a more dispersed approach to area defence and minimising the use of line defence.
One of the problems affecting the Ukrainians during defensive operations is the extensive length of the trench lines. Due to manpower and supply issues, it is not feasible to effectively man and equip all the trenches stretching along the front line. Therefore, it would be more advantageous to rely on area defence and, in some cases, perimeter defence in an attempt to control specific points.
- Regular Maintenance and reinforcement of infrastructure including roads and bridges.
The ability to reach the frontline via various routes is paramount as it limits the enemy’s capability to predict and intercept movements. Currently, only a few roads have been commissioned, posing a significant danger to transit that undermines logistical operations and overall operational capability.
- More systematic use of Security Forces concepts, use of QRF and unmanned guns.
Security forces and quick reaction forces are methods that could reduce the need for densely manned trenches. This could be supplemented by the introduction of unmanned and remotely controlled firing positions, such as GPMGs or grenade launchers. These weapon systems are currently under development, and their use will enhance units’ survivability.
- A drastic increase in the use of trench concealment, using unsophisticated methods where resources are scarce or in the absence of more specialised tools.
This is arguably the most crucial point: trenches and defensive positions must remain concealed. Commanders, leaders, and NCOs must ensure that trenches are not visibly exposed, evading cursory visual inspections conducted by the enemy using recognissance UAVs. Employing more sophisticated concealment measures when necessary is imperative. This includes keeping the trench well-maintained and deploying netting or other concealment materials wherever possible.
- Widespread use of trench target decoys for deception.
The central concept here is to construct multiple layers of protection around the defending unit. By deploying trench decoys, the aim is to divert the attention of FPV operators and instil uncertainty in the FPV pilot. This would have two main benefits, it would spare from attacks other areas of the defense position and would also consume the enemy drone stockpile.
References
[1]B. Daniele, “Data-driven analysis on FPV drone usage in the Ukrainian-Russian conflict”, Tochnyi, 2024. [Online] https://tochnyi.info/2024/01/fpv-data-analysis/ [Accessed: 02-22-2024].
[2]B. Daniele, “Update on FPV drone warfare (27-01-2024)”, Tochnyi, 2024. [Online] https://tochnyi.info/2024/01/update-on-fpv-drone-warfare-27-01-2024-2/ [Accessed: 02-22-2024].
[3] Z. Valery, “The commander-in-chief of Ukraine’s armed forces on how to win the war”, The Economist, 2023. [Online]. Available: https://www.economist.com/by-invitation/2023/11/01/the-commander-in-chief-of-ukraines-armed-forces-on-how-to-win-the-war . [Accessed: 02-22-2024].
[4] G. Matthew, “Stop Saying the Tank Is Obsolete Just Because Russia Sucks at Using Them”, VICE, 2022. [Online]. Available: https://www.vice.com/en/article/v7dkjm/stop-saying-the-tank-is-obsolete-just-because-russia-sucks-at-using-them?callback=in&code=YWU4ODI3NDUTMJHJMC0ZMTQ4LTG5YJMTYJC5YJRHMZQ2ZDLM&state=5b6ee9e91d004cf39e2a62be3c23d5ff. [Accessed: 02-22-2024].
[5] G. Elisabeth, “Are the once-vaunted Bayraktar drones losing their shine in Ukraine?”, Defence News, 2023. [Online]. Available: https://www.defensenews.com/global/europe/2023/10/31/are-the-once-vaunted-bayraktar-drones-losing-their-shine-in-ukraine/. [Accessed: 02-22-2024].
[6]The Economist, “FPV drones: weapons that changed the modern war”, The Economist, 2024. [Online]. Available: https://www.economist.com/leaders/2024/02/08/killer-drones-pioneered-in-ukraine-are-the-weapons-of-the-future. [Accessed: 02-22-2024].
[7]К. Саня , “FPV drones: weapons that changed the modern war”, Military, 2023. [Online]. Available: https://mil.in.ua/en/articles/fpv-drones-weapons-that-changed-the-modern-war/. [Accessed: 02-22-2024].
[9]https://www.historyonthenet.com/ww1-trenches-what-is-a-trench
[10]https://www.csis.org/analysis/ukraines-offensive-operations-shifting-offense-defense-balance
[11]https://www.osw.waw.pl/en/publikacje/analyses/2023-07-04/back-to-trench-warfare-day-495-war
[12] Field Manual 3-90, Tactics, May 2023, Headquarters, Department of the Army. https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN38160-FM_3-90-000-WEB-1.pdf
[13] Counter-Unmanned Aircraft Systems (C-UAS), August 2023, Headquarters, Department of the Army. https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN38994-ATP_3-01.81-000-WEB-1.pdf
[14] https://www.rferl.org/a/ukraine-anti-drone-gun-russia-war/31912255.html