TEL AVIV – Military strategists are identifying the subsurface as a decisive theater of modern conflict, as state and non-state actors increasingly utilize hardened underground infrastructure to neutralize traditional aerial and satellite surveillance.
The shift toward subterranean operations is driving a movement to categorize the underground as a distinct domain of warfare, termed “Subterra,” placing it alongside land, sea, air, space, and cyber. This conceptual shift recognizes that operating below the surface presents physiological and tactical challenges that cannot be solved by simply adapting surface-level military doctrine.
Traysar Industries, a firm co-founded by former Israel Defense Forces (IDF) Yahalom unit member Asher Katz and Principal Engineer Greg Johnson, is leading efforts to integrate high-end civilian engineering with military subterranean expertise.
Strategic Use of Subterranean Infrastructure
Adversaries are deploying underground networks to offset the technological advantages held by Western militaries, specifically in the areas of precision-guided munitions and real-time intelligence. By moving command centers, weapon stockpiles, and troop movements underground, these actors can prolong conflicts and survive initial strikes that would otherwise dismantle surface-level infrastructure.
For defense planners, this is no longer a niche concern. NATO members and U.S. combatant commands now routinely factor hardened tunnels, buried launch sites, and underground logistics hubs into targeting doctrine, alliance exercises, and procurement priorities, treating them as a core constraint on deterrence and escalation management.
Verified instances of strategic subterranean development include:
- China: The development of the “Underground Great Wall,” a vast network of hardened facilities designed for strategic depth and the concealment of nuclear and conventional assets.
- North Korea: Extensive military tunnel networks used to shield artillery, missiles, and leadership compounds from aerial bombardment.
- Iran: Hardened underground missile silos and nuclear-related complexes designed to resist bunker-buster munitions and complicate inspection regimes.
- Hezbollah: Fortified infrastructure in southern Lebanon used for clandestine troop movement, weapon storage, and cross-border attack preparation.
- Hamas: A sprawling tunnel system beneath Gaza used for operational mobility, command and control, and tactical surprise in urban combat.
These networks, while tactically local, have strategic consequences: they influence cease-fire negotiations, verification of arms-control commitments, and the confidence with which governments can assure their publics that hostile capabilities are being monitored and contained.
The Subterra Framework
Asher Katz argues that the underground must be treated as its own domain because the physics of the environment fundamentally alter combat. In the “Subterra” model, the subterranean environment is not merely a hiding place but a space for maneuver, logistics, and command, with its own doctrine, force structure, and rules of engagement.
According to Katz, the tactical differences include the total loss of GPS and traditional radio communications, restricted lines of sight, and the physiological stress placed on soldiers operating in confined, oxygen-deprived, or toxic environments. Militaries must therefore develop training standards, medical protocols, and safety regulations tailored to Subterra operations, rather than relying on improvisation by frontline units.
This emerging framework is beginning to intersect with existing governance architecture. Debates over proportionality in targeting, the protection of civilians, and the treatment of underground medical or humanitarian sites are now being tested against the obligations set out in the Geneva Conventions, which remain the core legal reference point for how states conduct and justify subterranean campaigns.
Engineering and Tactical Integration
The challenge of defeating hardened underground facilities requires a fusion of military intelligence and advanced civilian excavation technology. Greg Johnson, whose engineering background includes work at SpaceX and The Boring Company, notes that the gap in subterranean warfare is often an engineering one rather than a purely tactical one.
Defense ministries are increasingly pairing combat engineers with geologists, tunnel designers, and civil infrastructure specialists to translate commercial best practice into deployable capability. That shift is beginning to appear in classified acquisition documents, war-gaming scenarios, and requests for proposals issued to the private sector.
The current technical requirements for effective subterranean operations include:
- Detection and Mapping: Developing sensors capable of identifying voids and tunnel geometries through dense soil and rock, and integrating those data into real-time digital terrain models.
- Underground Mobility: Creating rapid excavation tools and transport systems to allow friendly forces to move through the subsurface without collapsing structures above.
- Robotic Systems: Deploying autonomous or remotely operated vehicles to scout tunnels, map hazards, and neutralize threats without risking personnel.
- Communications: Establishing mesh networks and signal-relay systems that function without line-of-sight to the surface, maintaining secure links between underground teams and surface commanders.
Industry executives say these capabilities are now influencing how border authorities, critical infrastructure operators, and emergency services think about underground resilience, blurring traditional lines between national security and domestic public safety planning.
The Expertise Gap
While technology such as robotics and advanced boring machines are critical, the primary vulnerability for modern militaries is a lack of specialized expertise. The IDF’s Yahalom unit provides a precedent for this specialization, focusing exclusively on combat engineering, tunnel detection, and demolition.
The integration of civilian mining and tunneling expertise is now viewed as a necessity to match the scale of subterranean construction seen in East Asia and the Middle East. That integration carries policy implications: governments must decide what knowledge can be shared with private contractors, how to regulate exports of sensitive excavation technologies, and where to draw lines between legitimate infrastructure projects and dual-use capabilities.
Militaries are currently evaluating new procurement and training pipelines to address the deficiency in subterranean operational knowledge. Defense officials describe a shift toward dedicated Subterra units, standardized certification for tunnel operations, and cross-border information-sharing with allies. For legislators and oversight bodies, the next phase will be ensuring that these rapidly evolving capabilities are matched by transparent doctrine and accountability mechanisms that reflect the realities of warfare beneath the surface.
