Concrete Castles: Urban Warfare in the 21st Century

Wells Benjamin

“You won’t find a new country, won’t find another shore.

This city will always pursue you.”

“The City”,  C. P. Cavafy

Introduction: Nothing New Under the Sun 

The concept of an urban war is often thought of as a modern phenomena. Images of Stalingrad and Fallujah capture the mind and promote the idea that urban warfare is a kind of uniquely modern environment for war, but this couldn’t be further from the truth. As long as humans have begun to gravitate towards centralized political structures, war has followed. Cities have always served as the political center of gravity for states. The ancient Greek word for city, polis, is where the word politics is etymologically derived from. As far back as the Old Testament, there are written accounts of urban warfare, with Joshua 6 depicting the Israelites besieging Jericho. Cities hold the center of a state's economic, political, and cultural power, and capturing them has often been the key strategic goal of military campaigns throughout history. The modern world is increasingly urbanizing, with 45% of the world's population now living in urban areas, a share twice as large as it was in 1950. Given the current trend of increased urban density alongside the historic precedent, the prevalence of urban warfare can only be expected to grow in the 21st century. Urban terrain represents a uniquely challenging environment for military operations that is fundamentally different from any other. Looking towards the role urban terrain has played in the Israeli invasion of Gaza and the Russian invasion of Ukraine can help provide a vital understanding of what urban warfare currently looks like in the 21st century, and how it may change in the future. 

Gaza’s Urban Nightmare 

The invasion of the Gaza Strip by Israel following the October 7 terror attack has resulted in a level of civilian suffering unseen in the Middle East since the fall of the Islamic State of Iraq and Syria (ISIS), with some of the brutality tied directly to the geography of Gaza. Prior to the war, over 75% of the Gazan population lived in the cities that dominate the small geography of the strip, a distribution that has greatly exacerbated the present humanitarian crisis. Cities are particularly advantageous for defenders willing to hide within civilian buildings, and Hamas has habitually used hospitals, schools, and mosques to cloak military infrastructure. Dense urban terrain provides a wide array of hiding places for fighters, particularly when soldiers are wearing civilian clothing. The overwhelming military advantage held by Israel pushed Hamas into using guerrilla tactics throughout the war, favoring ambushes and traps over direct confrontation with the Israel Defense Forces (IDF), a strategy only made possible by the dense cityscape of Gaza. 

A conventional military facing insurgents in control of a city rife with innocent civilians is not a new military challenge. When confronted with this situation, the attacking army is presented with two schools of thought in engaging with an enemy entrenched within urban terrain. The superior force can encircle the defenders and methodically clear each block of insurgents, as was seen in the war against ISIS in the 2016 Battle of Mosul. This approach requires time and planning, but can ideally result in a victory with minimal civilian casualties. Alternatively, the attacking force can systematically destroy enemy positions with artillery and airstrikes until there is nowhere left to hide, as was seen in the 1995 battle for Grozny between Russia and Chechen rebels. In the case of Gaza, the IDF has applied a mix of both. Early on in the war, Israel attempted to encircle and clear Hamas strongholds within Gaza, but faced considerable challenges in doing so. Urban terrain offers a unique level of three-dimensional space, wherein forces can position themselves anywhere from the top of high-rises to beneath the streets themselves. The unmatched verticality of urban spaces provided Hamas fighters the ability to conduct ambushes on exposed IDF troops from the safety of buildings, and then quickly retreat back into the sprawl. The extensive network of tunnels beneath Gaza compounded the challenge associated with clearing structures faced by the IDF, as it provided safety for Hamas fighters to maneuver in and out of battle. 

The subterranean network under Gaza is thought to stretch upwards of 350 miles and took decades to construct. Hamas leveraged this capability to push the IDF into a path of mass destruction on which it was keen to embark. Hamas correctly assumed the civilian casualties that would result from indiscriminate Israeli airstrikes would spark international condemnation and deepen the rift between Israel and Arab states. The terrain of Gaza is a critical factor in why the civilian casualties of this war were historically unprecedented for conflicts between Israel and Palestine. Urban environments are inherently filled with civilians, and this fact greatly complicates offensive operations conducted within cities. In the best of cases, civilians are evacuated prior to the start of battles; however, this was impossible given the refusal of Israel and Egypt to allow the evacuation of Palestinians. Buildings in dense urban environments offer an unparalleled level of cover to defending forces, and can be extensively trapped to prevent infantry from clearing them. The defensive depth of buildings, combined with tunnels that facilitated concealed maneuver throughout Gaza, contributed greatly to the terrible human cost of this war. 

Bakhmut: The Meat Grinder 

While the war in Ukraine has seen similar levels of wanton destruction of civilian infrastructure and massacres of innocent civilians contained within, the Battle of Bakhmut represents a starkly different case than that of Gaza. Bakhmut was a modest industrial town in the Donetsk region of Ukraine, with a pre-war population of  approximately 80,000. After the full-scale invasion began in 2022, Russian forces started advancing towards Bakhmut, and the city was partially encircled by July 2022. The Battle of Bakhmut that quickly followed grew into the longest and bloodiest battle in Europe since World War II, lasting eleven months and claiming a total of almost 70,000 lives. A majority of the civilians that previously inhabited the city had left prior to the fighting, allowing for the deadly nature of unrestricted full-scale war in an urban setting to take place. Bakhmut’s position as a logistical nexus for much of the Donetsk Front and entryway to the open terrain west of the city provided some strategic value for both sides; however, the true reasoning behind the city’s military importance for Russia was largely symbolic. Facing considerable setbacks after the first wave of Ukrainian counteroffensives, the Russian Ministry of Defense saw Bakhmut as a tangible political victory amid a war with increasingly stagnant frontlines. Unlike much of the frontline, which was made up of fiercely contested agricultural land and small villages, Bakhmut was a regionally important city that could serve to legitimize the annexation of Donetsk. In the propaganda game, capturing a treeline makes for a far worse headline than that of a city after all. 

The fighting within Bakhmut quickly took on an attritional character, in which Ukrainian military command saw an opportunity to use the defensive advantage of urban terrain to cause considerable Russian casualties. Many of the advantages held by the Russian army were negated by Bakhmut’s terrain, with tight city streets making armored assaults vulnerable and the cityscape blocking artillery. Russian forces began  to throw waves of ill-prepared infantry through narrow streets marked by Soviet-era high rises and industrial spaces that provided Ukrainian defenders cover and elevation. Each block was transformed into a makeshift fortress that could take weeks to capture, with heavy losses incurred for every apartment complex or elementary school gained. Even with Russian strikes that leveled buildings daily, the size of Bakhmut meant there was always another line of defense. Urban terrain multiplies the cost of offensive operations, and in many cases can not be avoided by attacking forces. Bakhmut was a central defensive node within a wide frontline, and as such, bypassing the city became operationally impossible for Russia. This case serves as a poignant lesson that even when an attacking force holds a considerable advantage in firepower, urban warfare heavily favors defenders. The dilemma of urban warfare is such that cities represent important objectives within military campaigns, but are uniquely costly to take. Even when a city is fully encircled for months, small defensive pockets can remain active, as was seen in the defense of the Azovstal steel plant within occupied Mariupol. Russia faced extreme losses in doing so, but eventually captured Bakhmut after months of fighting. This provided a political victory for the Kremlin, but was undertaken at a pyrrhic cost. 

Conclusion: The City Pursues 

Urban warfare is a defining theme of modern conflicts, and one that will only increase in prevalence as the world becomes increasingly urbanized. The terrain of cities provides such a strong defensive advantage that even in cases of extreme conventional overmatch, as was seen in Gaza, dedicated forces can hold out for extended periods. Whether faced in a full scale or counterinsurgent scenario, urban warfare holds a plethora of unique challenges that modern militaries must account for. Future conflicts will be defined by the urban battles that they are centered on. If China were to invade Taiwan, it would face an island defined by mountains and cities, presenting a monumental military challenge. Taiwan is more urbanized than even Gaza is, with 80% of the 23.5 million Taiwanese living in urban areas. Regardless of where the next major conflict occurs, the city will always pursue it.