Two demographic trends have recently caught the attention of defense planners: the rapid urbanization of the world’s population and the move of people to the littorals. By 2050, two-thirds of the world’s population is projected to live in cities. According to the 2017 United Nations Ocean Conference fact sheet, an estimated 40 percent of the world’s population already lives within 70 miles of the coast. The explosive growth of coastal cities, combined with the growing possibility of near-peer conflict and the persistent problems of terrorism and rogue states, means that the Sea Services will likely face difficult urban combat in the coming decades. (See N. Nethery, “Prepare to Fight in Megacities,” pp. 56–60, August 2018.)
Urban combat has always been the slowest and most difficult type of warfare. Within the past century, the siege of Leningrad during World War II lasted 872 days, the siege of Sarajevo lasted 1,425 days, and the Second Battle of Fallujah—an extremely lopsided fight in the U.S. military’s favor—lasted 46 days. The time and resources required for urban combat mean that the side that can capture cities the fastest and most efficiently will have a huge advantage.
Battlefield commanders have long understood this. Saladin, who expelled the Crusaders from Jerusalem in 1183, had so much success because he was able to capture his enemies’ strongpoints before their field armies could react. Eighteenth-century armies developed such effective siege techniques that they were able to adopt a more fluid form of field maneuver than had ever existed. For the Navy and Marine Corps today, being able to rapidly capture urban areas along the littorals would allow U.S. forces to seize enemy centers of gravity and facilitate seaborne invasions. The 1950 Inchon landings show what is possible when a force can take even a well-defended city.
Networked Urban Combat
How can technological developments assist in future urban combat? Urban combat is as close to a pure infantry fight as can be found in modern warfare. Air, armor, artillery, and naval fires have their place, but these are much less effective in city environments than they are in other types of combat. Armor cannot maneuver well and remote fires are less effective against well-fortified urban positions. City fighting also occurs at such close quarters that these other arms often cannot be employed even when they would be effective. Chechen militants used this to their advantage in the three Battles of Grozny between 1994 and 2000, attacking Russian infantry from close range and immobilizing Russian tanks and armored personnel carriers while attacking from well-fortified positions that could resist artillery bombardment. Only by slow, bloody, street-by-street fighting were the Russians able to retake Grozny.
Any technology that increases an attacking infantry’s mobility and organic firepower offers a potentially decisive advantage in urban combat. Unmanned ground vehicles (UGVs) are one such technology. Small tracked unmanned vehicles that climb stairs and piles of rubble could be equipped with rockets, machine guns, and grenades to provide suppressing fire to maneuvering squads. Battering ram UGVs could breach doors and break through walls to create mobility corridors through a city. Still others could ferry supplies to troops and evacuate casualties to medical facilities, while amphibious versions could extend supply lines to ships offshore. UGVs have been in development for a long time, with the Army’s Multifunctional Utility/Logistics and Equipment (MULE) vehicle and the Marine Corps’ Gladiator potentially filling these roles. Once prototypes become operational, their competitive advantage will incentivize many nations to develop or acquire their own versions.
The decisive advantage will not go to the country that develops the most technically advanced UGV, however, but to the one that networks them the best. Just as combined arms produce far greater effects than the sum of their parts, networked UGVs acting in concert with humans and other machines will be a formidable force on the battlefield. Unmanned aerial vehicles (UAVs) can act as spotters, communications relays, and surveillance platforms for armed UGVs, which then autonomously develop their own firing solutions. Taking a page from machine learning, these networked teams could run automatic after-actions following every engagement and use the results to improve their algorithms, quickly working out best practices and identifying enemy tactics, techniques, and procedures.
As networked UGVs, UAVs, and ground troops evolve into coherent teams, schemes of maneuver will become much more flexible and decentralized. Machine learning teases out subtle patterns from endless repetition, meaning networks will be able to determine weaknesses in the enemy’s defenses and adjust on the fly. Assaults might take a more circuitous course through a city, bypassing strongpoints and encircling concentrations of enemy troops. Multiple teams might progress along parallel axes, probing for weaknesses and surging through gaps when they find them, similar to the breakthroughs of blitzkrieg warfare in the 1940s. Although defensive tactics will evolve and adversaries defending urban positions will also use UGVs, the inherently dynamic nature of network effects gives the advantage to the attacker.
In the long term, the disruptive effects of new technologies come not from immediate results on the battlefield but from how the other side reacts to them. Military commanders did not get an unbeatable advantage from modern artillery and machines guns, but these innovations did force armies to dig in and fight a very different type of war. Networked UGVs likewise will not simply allow attackers to roll through enemy defenses, but they will alter the nature of the defense. The emphasis will be on attacking enemy logistics, preventing them from bringing their assault forces to bear. This matches historical patterns, in which cities became delaying obstacles in much broader schemes of maneuver.
In the meantime, it is important to understand how best to develop networked UGVs. Flexible and effective networks cannot be designed from the top down, but instead require a lot of direct input from infantry noncommissioned officers and junior officers who can get their hands dirty with different variants of UGVs; communications personnel who can experiment with command-and-control regimes; and logisticians who can see what is most sustainable. Given the United States’ ongoing engagements in the world, the best way to do this might be to push robotics developers to forward theaters, where they can tinker with existing designs in response to requests from troops on the ground. Some technical sophistication might be sacrificed, but when network effects are factored in, good-enough designs with quick development cycles will beat technological marvels.
The United States has not fought a campaign since Inchon in which success depended on the speed of urban operations. Years of counterinsurgency operations have lulled the U.S. military into neglecting this aspect of warfare, but the neglect must end. U.S. rivals surely are focused on it. Footage of quarantined Chinese cities in the early months of 2020 showed unmanned vehicles roaming the streets, controlling crowds, monitoring installations, and performing other normally human tasks. UGVs are already here, operating in urban environments. The Marine Corps should acquire them and develop tactics, techniques, and procedures to use them in urban combat at scale.
