Digging Deeper: How Underground Infrastructure Undermines US Strikes and Empowers Adversaries
Introduction
Operation Midnight Hammer and Operation Epic Fury collectively reveal something interesting about the future of modern warfare. In June 2025, Operation Midnight Hammer marked several firsts: the largest strike using B2 bombers, the longest continuous flight of B2 since 2001, and the first mission to demonstrate the utility of massive ordnance penetrating bombs (MOP), dropping a total of 14 MOP on two Iranian nuclear facilities—Natanz and Fordo. Building on this, Operation Epic Fury has seen a record number of strikes, amounting to more than 13,000 targets destroyed (as of April 2026), yet Iran has not fully yielded to US pressure. Despite the significant degradation, Iran has demonstrated a capacity to absorb punishment and persist. Both operations signaled more than continued US dominance and capabilities; they signaled to adversaries worldwide that safety and survivability lie underground.
Going underground is not a new or revolutionary tactic. In ancient times, nations went underground to escape, shield themselves, and survive overwhelming foes. Traditionally, subterranean capacity resembled tunnels that forces used to bypass fortifications and achieve a degree of surprise by emerging from areas thought to be immune to attack. What has changed is the scale and sophistication. Where ancient tunnels once moved troops, modern underground complexes are now characterized as “missile cities” and an “underground great wall,” engineered to shelter entire military ecosystems from the world’s most advanced strike capabilities.
This essay argues that underground infrastructure has meaningfully undermined the operational effect of both Operation Midnight Hammer and Operation Epic Fury — and that this limited effect will likely accelerate a behavior already demonstrated by US adversaries: the deliberate placement of critical military infrastructure underground. China and North Korea have long pursued this strategy. What Iran’s resilience now illustrates is that this strategic approach works. As the operational returns of US precision strikes diminish against buried targets, adversaries with an established pattern of underground construction have every incentive to dig deeper and faster to be beyond the reach of US strikes, eroding a cornerstone of the US strategic playbook.
Designed to Survive
Iran’s underground infrastructure is, above all, an architecture of survival. The scale alone reinforces this intent. Decades of digging and construction have resulted in Iran having more than 30 underground missile cities integrated into a vast tunnel system with more than 107 tunnel exits. Many of these bases are carved deep into mountains, atop a natural granite shield. At the beginning of Operation Epic Fury, it was estimated that Iran had over 470 ballistic missile launchers, with Israel claiming to have destroyed or disabled more than 60% of that total. However, data suggest that half of Iran’s launchers are still operational, and tunnels thought to be destroyed are largely reopened. The decades of preparation are starting to demonstrate their value, and the beneficiary is Iran, not the US.
The Yazd base illustrates this resilience in concrete terms. The Yazd base, located roughly 500 meters below a granite mountain in central Iran, is estimated to be beyond the reach of US MOP technology. Moreover, this facility includes an “automated rail system operating through tunnels connecting assembly areas, storage depots, and concealed exits.” Iranian state media footage, showing a facility with similar characteristics as Yazd, demonstrated the efficacy of missile launchers that are rapidly “transported by trucks, brought out for launch, and then quickly returned underground.” This suggests that the Yazd base, and comparable installations, demonstrate the capacity to absorb strikes and continue to retaliate, which collectively support Iran’s survivability.
Limiting Coercive Power
It is easy to view the vast destruction caused by precision strikes during Operation Midnight Hammer and Operation Epic Fury as a meaningful mechanism to coerce; however, destruction does not guarantee this. Shortly after the attacks, President Trump stated that Operation Midnight Hammer achieved “complete and total obliteration” of Iran’s nuclear sites, and that recovering the uranium stockpiles would be “a long and difficult process.” Yet CNN reported that the US did not strike one of Iran’s largest nuclear sites at all, because its depth put it beyond the reach of MOP technology. Given Iran’s decades of investment in underground construction, this suggests that this is by design, not luck. A military’s reluctance to strike a target it knows sits beyond reach sends its own signal: that US capabilities, and therefore US decision-making, are influenced by where an adversary chooses to bury its infrastructure.
The same pattern is demonstrated even where the US did strike. Within a Schelling framework, coercion works not by destruction alone but by the target accurately perceiving the pain inflicted and/or the “future pain” yet to come. That logic weakens the moment the target demonstrates it can absorb significant pain inflicted by the coercer and remain operational. Trump’s goals with Iran, from Operation Midnight Hammer through Operation Epic Fury, treated strikes as exactly that kind of signal: a demonstration of US power designed to alter Iran’s behavior. The US targeted underground missile storage sites along the coast, yet declassified assessments tell a sobering story: Iran regained access to roughly 90 percent of its underground missile storage and launch facilities. Trump similarly declared Iran’s nuclear capacity “obliterated,” but once the full effects could be assessed, a stark gap emerged between physical destruction and strategic effect. Iran’s underground infrastructure, in short, called the US’s bluff. The duality and utility of hardened underground networks is clear: they structurally shielded critical assets from kinetic strikes and diplomatically shielded Iran from coercive pressure, transforming a demonstration of overwhelming force into an exposure of its limits
A Global Pattern
China
US strikes in Iran are reaching beyond where they are landing. Nations like China are internalizing lessons from Operations Midnight Hammer and Epic Fury, reinforcing an already established strategy. China’s priority on underground infrastructure is not new. It began in the 1980s and gained renewed urgency as China observed US and allied airstrikes during the Gulf War. This urgency has not stopped since then. From 2015 to 2016, China expanded its underground facilities program to foster greater survivability through redundant “nodes” that enable continuous, sustained command-and-control communications (even when other sectors are degraded). According to the Asian Times, Chinese sector experts have suggested, in light of Operation Midnight Hammer, that they dig deeper, placing strategic energy and defense assets further underground. This just doesn’t change strategy for the US; it completely turns decades of demonstrated capabilities and power projection on its head.
China has not merely adopted an underground strategy; it has integrated it into broader military strategy. For instance, the People’s Liberation Army’s (PLA) air force has 13 or more “super-hardened” bases tunneled into hillsides. PLA Naval bases, such as Jianggezhuang and Yulin, provide cover for ballistic missile submarines and aircraft carriers, enabling easy access into the South China Sea. With critical naval warships and jets protected, preemptive US strikes that are aimed at quickly taking out critical targets are undermined. Even future PLA command centers are aligning to continue underground structures. Under construction since 2024, the new PLA command center is reported to be ten times larger than the Pentagon and is estimated to have fortified bunkers to protect key PLA personnel and leaders of the Chinese Communist Party (CCP). Together, this should signal to Washington that strategies centered on precision strikes may prove inadequate and, at best, move objectives forward only sluggishly.
North Korea
In a similar light, traumatized by witnessing US superiority in the Korean War, North Korea has turned its trauma into a cornerstone of its national strategy. During the Korean War, North Korea experienced firsthand the devastating power of US strikes on its industrial base and infrastructure. This stark realization is believed to have influenced North Korean Founder Kim Il Sung to direct future key infrastructure to be built underground. Decades later, this goal is inherent to North Korea, with much of its military capability remaining underground, concealing an extensive network of facilities, including troop tunnels, hardened artillery positions, underground air bases, leadership shelters, vehicle and supply storage facilities, and protected missile and submarine installations. Nonetheless, much like China, this strategy, born of historical trauma, has proven to be a significant strategic asset, as analysts suggest that the depth and hardening of these facilities meaningfully limit the effectiveness of US strikes and MOP technology, thereby reducing Washington’s ability to use military force as leverage in any future conflict.
Conclusion
The idea of this article was not to reveal a grand and novel concept in warfare tactics; rather, it serves as a meaningful warning, drawing on available information to reveal future implications.
Operation Midnight Hammer and Operation Epic Fury demonstrated operational reach and US military power, and in many respects, it achieved this. However, it also demonstrated a deeper limitation when critical targets are out of reach. And as the US continues to equate destruction as a strategy, underground infrastructure represents a meaningful leverage against US traditions of strikes.
Some commanders anticipate a future where threats are underground in some capacity, and the US should plan accordingly. Yet the more the US demonstrates its precision-strike capabilities, the more it accelerates adversaries’ investment in countermeasures that blunt those capabilities. In essence, each operation becomes a tutorial. If the US does not develop new capabilities, doctrines, or diplomatic tools to address this shift, it risks entering future conflicts with a playbook its adversaries have already solved for. Therefore, the underground strategy is not a passing adaptation but a structural change in how US adversaries intend to fight, survive, and endure.
