As Force Exposure Becomes Perilous, Wars Become Long

If it was ever safe to assume that wars would be quick and decisive, it is increasingly difficult to do so. In Ukraine, Iran and Gaza, attacking forces have struggled to achieve decisive outcomes, despite substantial technological advantages.

The answer may in part lie in a struggle over supply lines, which look even more important than they always have been.

The main driver of the change we’re seeing is no single technology but the convergence of technical developments that have dramatically increased the danger of exposure on the battlefield. Persistent surveillance, inexpensive drones, AI and precision-strike systems have made it progressively harder for military forces operating on the surface to remain undetected. Once detected, they are at high risk of continuous observation and increasingly inexpensive precision attacks.

The response has been to shift critical military functions beneath the surface. Command, logistics, production, communications and strike forces are increasingly being protected in tunnels, bunkers and caverns.

Defenders generally have the advantage of operating from territory they control, where they can prepare positions and, given sufficient time and resources, move critical functions underground. Attackers, by contrast, must expose forces and equipment when advancing to seize ground. These movements are increasingly vulnerable to surveillance and precision strikes. Underground targets, meanwhile, remain difficult to neutralise, often requiring sustained operations on the surface – the very operations that have become increasingly costly and dangerous.

The balance has thus shifted towards defence in important respects, recalling the Western Front during much of World War I, where even overwhelming numerical superiority guaranteed no breakthrough, let alone decisive victory.In Ukraine, soldiers at the front are in dugouts. Further back, so are command posts. In the cities, factories are dispersed and hidden, often in basements. The Russian army is much larger than Ukraine’s, but its advances have been slow and costly. It has also failed to cut off the supply flows entering Ukraine across its western borders.

Iran has deeply buried command facilities, stores of strike missiles, and supporting infrastructure – such as the underground missile storage and launch complexes in Kermanshah and Isfahan, or hardened nuclear facilities like Fordow and Natanz. Even the United States, with command of the air, highly practised armed forces and extensive capacity for surveillance, intelligence and precision strike, is challenged in rooting all this out. Meanwhile, Iran can still strike U.S. and allied forces – and civilians – with missiles or strike drones that are suddenly wheeled out from underground and launched.

In Gaza, underground facilities have greatly complicated Israeli military operations. Yet, notably, Gaza’s small, geographically confined territory has given Israel greater scope to restrict supplies to Hamas’s underground network than Russia has had to isolate Ukraine’s.

For the most part, supplies must move on the surface.

An attacker’s principal planning question may no longer be whether military superiority is sufficient to quickly defeat the defender’s forces. It probably won’t be if the defender has gone effectively underground. Instead, the attacker should ask whether it can deny supply that keeps the defender’s subterranean operational system going.
People in underground positions still need food. Soldiers also need a flow of equipment, such as ammunition and drones, and energy – electricity, or fuel for generators. Where sophisticated equipment is kept underground, it may need spare parts. Subsurface manufacturing must be supplied with components and materials.
Interrupt the flow of all that – isolate the facilities completely – and the defender weakens.

This points to a central lesson for any prospective attacker: against a well-entrenched defender, military superiority alone may not deliver a quick and decisive victory if the attacker cannot sufficiently disrupt the supply networks sustaining the defender’s underground capabilities.

If an attacker cannot seal every border, the defender’s underground system may long survive with surface resupply. Where comprehensive isolation is impossible – as the war in Ukraine illustrates – military superiority may not deliver a rapid victory.

For defenders, the task is to stock underground facilities for a siege and secure supply lines from friendly neighbours. That costs money and requires effective foreign diplomacy.

From where we stand, it is impossible to know how far the balance between attack and defence is shifting or will shift. One strategic implication is nevertheless clear: the ability to sustain underground capabilities may prove decisive in determining whether military superiority can be translated into a rapid victory.

John D Pappas is a Ph.D. fellow, 1985, of Columbia University in international economics and vice president for academic research at the think tank Ark of Holistic Education of the Armed Forces, Athens, Greece, which operates under the aegis of the chief of the Hellenic National Defence General Staff.

Image: An overturned car sits on a section of a destroyed bridge after a strike in Hormozgan province, southern Iran, Saturday, July 18, 2026. (Mahdi Negahban/Mehr News Agency via AP)

AI contributed no ideas to this article – John Pappas.

This article appeared originally at The Strategist (ASPI).