Small Wars Journal

Drone Swarms and Amphibious Operations

Tue, 05/30/2023 - 2:26am

Drone Swarms and Amphibious Operations

Zachary Kallenborn

If war breaks out between China and the United States over Taiwan, amphibious operations will likely play a defining role. If China hopes to annex Taiwan, China will almost certainly require an occupational force. That will require China to move land forces across the Taiwan Strait. Likewise, if the United States wishes to provide land reinforcements, those forces must cross most of the Pacific Ocean and land on potentially hostile beaches, depending on the scope of Chinese control. Recent RAND war games suggest drone swarms could be decisive.

Drone Swarm

“Drone Incoming” – US Forces assess drone swarm potentials at National Training Center, 8 May 2019. Source: Defense Visual Information Distribution Service, Public Domain.

Future drone swarms could play an important role in conducting and defending against amphibious operations. Drone swarms are well-equipped to carry out attacks on widely distributed, lightly armored transport. Plus, they could be quite useful in popping adversary air and missile defense bubbles and supporting/countering landing forces. As the technology is still developing, reconnaissance and security, followed by light attack are the most likely applications in the short term.  

What Drone Swarms Offer

The military value of drone swarms comes from the ability to mass, disperse over broad areas, and complexity at substantially lower cost than manned aviation. Drones are cheap, so a drone swarm can hold thousands; drone communication lets them spread out to search for targets; and the drones may be equipped with different payloads that integrate into a single system. The low-cost means drones are relatively expandable, and so can be used to mass attacks and overwhelm targets. The trade-off is often small payloads, especially for massive swarms. These attributes make them quite effective for amphibious assaults.

A large-scale amphibious assault against or in support of Taiwan will likely require massive amounts of transport craft to connect land forces from ground to ground. By nature, transport crafts are likely to have limited armor and defenses, especially if they are mass-produced at a low cost to support a big operation. That makes them easy pickings for a drone swarm. A successful hit against amphibious assault vehicles packed butt-to-butt would cause significant harm, even with a small explosive payload. Although transport ships would be escorted, one great value of drone swarms is the ability to overwhelm defenses. Even if defenses manage to shoot down half the drones, the half that get through could still wreak havoc.

Drone swarms can support assault forces too. Landing forces are likely to be particularly vulnerable when connecting from sea to shore. A swarm of cheap, disposable drones could be quite useful in distracting, suppressing, and overwhelming any defensive forces. Long-range unmanned surface vehicles accompanying connectors could launch swarms of loitering munitions that search landing areas for enemy targets, and coordinate strikes on any that show up. That could include defense against aerial threats too: Russia’s Lancet-3 loitering munition is reportedly intended to create aerial minefields, and a similar concept could be used to provide temporary air defense for landing marines.

Drones could be equipped with emitters to increase their electronic signature, giving an appearance of a much larger force. Such a drone swarm could be used in deception operations to draw adversary attention away from more critical efforts, deplete enemy air defense munition stocks, or help increase survivability for more valuable manned craft.  The Drive’s War Zone recently reported on Leonardo, an Italian defense contractor, demonstrating an autonomous drone swarm equipped with BriteCloud active decoys. The decoys detect incoming enemy radar pulses, then mimic the signal to look like a false target. Such decoys will be especially useful in a future conflict with China with its emphasis on anti-access, area-denial.

Drone swarms also offer dispersed situational awareness that could be useful for crisis response, amphibious withdrawal, and amphibious raids. Drones could spread out and coordinate searches around evacuation sites to watch for attacks or incoming evacuees. The UK Army, for example, has been exploring small groups of drones for perimeter defense. The same drones may disperse over a disaster area to support damage assessments, search for survivors, or even provide medical aid. Or a drone swarm might search through a dense jungle to provide awareness ahead of an advancing force, as one stunning recent video in the South China Morning Post illustrates.

The Challenges of Drone Swarms

Of course, drone swarms are not without their challenges and limitations. Probably the biggest is simply logistics—drones require resources. A ten thousand drone swarm needs to be transported too. That means taking up limited cargo room or creating bespoke drone motherships. The transport systems are also potential vulnerabilities, where adversary attack could destroy the whole swarm. Depending on how long the amphibious assault takes, power for smaller drones may be a challenge. Smaller quadcopter drones may not even last an hour before needing a recharge. Motherships could help with that, but it adds another layer to the planning difficulty. As with weather delays on D-Day, so too may weather impact drone swarm use. Strong winds or rain may limit or prevent drone impact. Although even small drones can be weatherized, the costs go up, and drone stocks will likely go down.

Production and sustainment will also be challenges. The cheap, disposable mass that drone swarms offer means drones will readily be shot down or destroyed, requiring continued production and sustainment to provide long-term support. For example, RUSI estimates that Ukraine loses approximately 10,000 drones per month. Sustainment is likely a particularly acute challenge for using drone swarms in amphibious operations. Especially if the amphibious forces are assaulting a city. Amphibious forces may not have large airfields to bring in replacement drones in large quantities, and sea-based resupply may be slow. Plus, drones and any mothership may need to be repaired, maintained, and powered. Unfortunately, drones cannot survive on crayons.


As drones become an increasingly defining feature of warfare, warfighters and analysts involved in planning, executing, assessing, analyzing, and defending against amphibious operations need to understand the implications of the technology as it becomes more sophisticated. The challenge is that drones and drone swarms are applicable to virtually every amphibious mission, and operation on both offense and defense. Plus, the United States and adversaries are also developing drone counter-measures, and drone counter-countermeasures whose applicability will vary for each. Further exercises, war games, modeling and simulation, and other techniques will all be needed to understand where drone swarms pose the most threat and offer the most opportunity for amphibious warfare. The next world war may be decided based on who finds the best answer.

Thank you to Josh Bryan for providing useful feedback on the piece. All remaining errors or poor turns of phrase are the author’s own.

Categories: drones

About the Author(s)

Zachary Kallenborn is an Adjunct Fellow (Non-resident) with the Center for Strategic and International Studies (CSIS), Policy Fellow at the Schar School of Policy and Government, Fellow at the National Institute for Deterrence Studies, Research Affiliate with the Unconventional Weapons and Technology Division of the National Consortium for the Study of Terrorism and Responses to Terrorism (START), an officially proclaimed US Army "Mad Scientist," and national security consultant. He has published over 60 articles in a wide range of peer-reviewed, wonky, and popular outlets, including the Brookings Institution, Foreign Policy, Slate, DefenseOne, War on the Rocks, the Modern War Institute at West Point, Terrorism and Political Violence, and Parameters. Journalists have written about and shared that research in the New York Times, the AP, NPR, Forbes, Politico, Al Jazeera, the Independent, Blick, Newsweek, the New Scientist, WIRED, and the BBC, among dozens of others in dozens of languages.