John Spencer, chair of urban warfare studies at the Modern War Institute and a founding member of the International Working Group on Subterranean Warfare, together with Colonel Drew Craig of NATO’s Allied Rapid Reaction Corps, have produced a timely and necessary corrective in their 12 August 2026 article “Digging Below the Death Zone: The Underground War in Ukraine.”
While the global defense community remains fixated on the spectacular proliferation of first-person-view drones, loitering munitions, and AI-enabled targeting that have rendered the surface of the Ukrainian battlefield a near-perfect “death zone,” Spencer and Craig force us to look downward. Their central thesis is straightforward and historically grounded: when firepower and persistent surveillance make the surface intolerably lethal, armies dig.
Ukraine and Russia have done so at industrial scale, transforming trenches into interconnected tunnel networks, buried command posts, logistics corridors, medical facilities, and even drone production sites. What emerges is not a niche engineering problem but a fundamental adaptation that reopens axes of maneuver, restores a measure of surprise, and challenges the very assumptions of the transparent battlefield.
Viewed through the framework of the generations of war and the enduring principles of maneuver warfare and Mission Command, the Ukrainian underground war is far more than defensive shelter. It is an operational response to a sensor-shooter revolution that has driven conventional surface operations toward something resembling industrialized attrition—Second Generation Warfare characteristics in a twenty-first-century guise. The solution has been to create a subsurface domain in which Third Generation maneuver logic can again operate, enabled by the decentralized initiative that defines true Mission Command.
Spencer and Craig open by acknowledging the dominance of the aerial domain in public and institutional discourse. Fiber-optic, jam-resistant drones with thermal sensors, satellite constellations, acoustic arrays, and AI-assisted targeting have compressed the kill chain to minutes. In sectors around Pokrovsk, drones have accounted for as many as 80 percent of casualties.
Soldiers describe a thirty-kilometer “death zone” in which any movement above ground risks near-immediate detection and destruction. This is the logical culmination of the “transparent battlefield” that theorists have long predicted. When every vehicle, trench line, and concentration of troops can be seen and struck, the surface favors the side that can mass precision fires and sensors—an inherently attritional dynamic.
This reality echoes the Western Front of 1915–1917 more than the fluid campaigns of 1940 or 1991. Firepower dominance forced both sides into elaborate subterranean systems then, just as it does now. The difference lies in the quality of the sensors: World War I lacked continuous overhead observation; Ukraine faces a persistent, multi-spectral, AI-fused surveillance network. The result is the same adaptive pressure: survival and combat effectiveness migrate underground.
Spencer and Craig correctly situate Ukraine within a long pattern. The mining operations beneath Messines Ridge and the Somme, the Cu Chi tunnels of the Viet Cong (approximately 250 kilometers of interconnected command posts, hospitals, and fighting positions), Hamas’s politico-military tunnel complex under Gaza, Hezbollah’s hardened systems in southern Lebanon, North Korea’s thousands of underground facilities, and Iran’s buried nuclear and missile infrastructure all demonstrate the same logic. When the surface becomes a killing ground, the subsurface becomes both sanctuary and avenue of approach.
What distinguishes the Ukrainian case is scale, sophistication, and the integration of civilian industrial capacity. Ukrainian forces have moved beyond improvised field fortifications to multilevel, reinforced facilities equipped with fiber-optic communications, ventilation, and concealed corridors that allow movement between positions without exposure. Civilian tunneling and construction firms—Automagistral-Pivden’s thirty-kilometer complex near Pokrovsk, Metinvest’s underground hospitals, and associations of real-estate developers—have been mobilized because military engineers alone cannot deliver the required volume and depth.
Russian forces have constructed vehicle-capable underground corridors near Zaporizhzhia and elsewhere, and have repeatedly exploited existing industrial infrastructure: gas pipelines near Sudzha and Kupiansk, and kilometers of sewer pipe prior to the capture of Avdiivka. These are not romantic “rat wars”; they are deliberate engineering solutions to a reconnaissance-strike complex that has made surface movement prohibitive.
Maneuver warfare, properly understood, seeks to shatter the enemy’s cohesion and decision cycle rather than destroy him through cumulative attrition. On the transparent surface, the defender’s ability to see and strike rapidly neutralizes many classic maneuver techniques. The underground domain restores several critical advantages.
First, it provides protected mobility and logistics. Troops, ammunition, and even manufacturing capacity can shift between positions without continuous exposure to the drone swarm.
Second, it creates genuine surprise. Infiltration through pipelines and sewers allows forces to appear inside or behind defensive lines, disrupting the enemy’s orientation and decision-making—the classic Boydian OODA loop exploitation.
Third, it forces the opponent to divert scarce resources to tunnel detection, flooding, mining, and ambush, thereby diluting the concentration of sensors and fires on the surface.
In short, the subsurface becomes an additional axis of approach that the sensor-saturated surface cannot easily close.
This is classic Third Generation Warfare logic applied to a new physical domain. Just as the German stormtroopers of 1918 used infiltration tactics to bypass strongpoints, modern forces use tunnels and pipes to bypass the death zone. The difference is that the “strongpoint” is now the entire observed surface.
Mission Command—decentralized execution based on shared understanding of commander’s intent—is both more necessary and more difficult underground. GPS is denied. Satellite communications are blocked. Line-of-sight radios are severely degraded. The physical environment itself (limited air, darkness, structural risk, disorientation) imposes constant friction. Under these conditions, only units and leaders trained to operate with high initiative, mutual trust, and a clear understanding of the higher purpose can succeed.
Spencer and Craig’s description of Ukrainian adaptation implies exactly this cultural requirement. Rapid construction of sophisticated facilities by mixed military-civilian teams, the ability of small groups to clear and exploit kilometers of sewer or gas pipe, and the continuous evolution of tunnel networks all demand lower-level initiative within a coherent operational concept. Centralized, detailed control—the hallmark of Second Generation industrial warfare—cannot function effectively in the labyrinth. Mission Command is not optional; it is the only viable command philosophy once forces move below the surface.
The Ukrainian experience is not an aberration. As sensors proliferate and precision strike becomes cheaper and more ubiquitous, every peer or near-peer conflict will generate similar pressures. NATO’s Eastern Flank Defensive Initiative already reflects awareness of the need for protected underground infrastructure. Future force design, doctrine, and training must treat the subterranean domain as a distinct battlespace requiring specialized engineering, navigation, communications, medical, and leadership competencies.
For the U.S. Army and its allies, this means moving beyond episodic “tunnel warfare” training modules. It requires embedding subterranean operations into the larger framework of maneuver warfare and Mission Command education. Officers and NCOs must understand that the underground is not merely a place to hide; it is a domain in which combat power can be preserved, repositioned, and projected in ways the transparent surface no longer permits. Outcomes-based learning focused on adaptive problem-solving under extreme friction—precisely the approach long advocated for Professional Military Education reform—is the only way to prepare leaders for this environment.
Spencer and Craig close with a stark observation: armies that cannot survive above ground must adapt below it. Their article is a warning and an opportunity. The side that masters the integration of surface sensors with subsurface maneuver, that institutionalizes the cultural prerequisites of Mission Command in the dark, confined spaces beneath the death zone, will hold a decisive advantage in the conflicts to come. The generations of war have not been abolished by drones; they have been driven underground, where the principles of maneuver and decentralized command remain as relevant as ever.
John Spencer and Drew Craig, “Digging Below the Death Zone: The Underground War in Ukraine,” Modern War Institute, 12 August 2026, https://mwi.westpoint.edu/digging-below-the-death-zone-the-underground-war-in-ukraine/.
Ibid. On the “death zone” and drone casualty rates, see also contemporaneous reporting cited within the article from Reuters graphics and Le Monde.
For historical parallels drawn by Spencer and Craig, see their discussion of Messines Ridge and the Somme (World War I), the Cu Chi tunnels (Vietnam), Hamas infrastructure in Gaza, Hezbollah systems, North Korean underground facilities, and Iranian hardened sites. Primary supporting sources linked in the original article include History.com on Cu Chi and Washington Post reporting on Gaza tunnels.
Specific Ukrainian examples—Automagistral-Pivden’s thirty-kilometer complex near Pokrovsk, Metinvest underground hospitals, and Russian pipeline/sewer infiltrations near Sudzha, Kupiansk, and Avdiivka—are detailed in the article with supporting links to Wall Street Journal, Radio Free Europe/Radio Liberty, Business Insider, and Institute for the Study of War assessments.
On the conceptual linkage to maneuver warfare and the OODA loop, see John R. Boyd, “Patterns of Conflict” (briefing slides, various editions); and William S. Lind et al., “The Changing Face of War: Into the Fourth Generation,” Marine Corps Gazette (October 1989). For Mission Command doctrine, see U.S. Army ADP 6-0, Mission Command: Command and Control of Army Forces (current edition).
For the broader argument that sensor proliferation drives forces underground and elevates the subterranean domain, compare Spencer’s related Substack essay “The Next Domain of Warfare Lies Underground,” 20 May 2026,
https://mwi.westpoint.edu/digging-below-the-death-zone-the-underground-war-in-ukraine/?fbclid=IwY2xjawTuqelwZG9mBWV4dG4DYWVtAjEwAGJyaWQRMXU3OWNMN1lLcDdrZGtYSzVzcnRjBmFwcF9pZBAyMjIwMzkxNzg4MjAwODkyAAEe_xkkhgHlCR-I02IvfN7d4pIUzEWKkYLCIHJVPN08z2IrCpjP_Jl0DdSQOH0_aem_0md7zYq6N-VosQHSFB4zxQ
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