Swarms over the Strait

Introduction

On battlefields in Libya, Nagorno-Karabakh, and Ukraine, combatants have used uncrewed aerial vehicles (UAVs), or drones, to great effect, leading some analysts to conclude that they are fundamentally changing the character of war.¹ In Libya, a 2019 offensive by General Khalifa Haftar’s Libyan National Army (LNA) was supported by Chinese-made drones, leaving the United Nations–backed Government of National Accord (GNA) clinging to power in Tripoli. Then, in late 2019, Turkey provided the GNA with Bayraktar TB2 medium-altitude drones and air defenses, enabling GNA forces to control the skies over Tripoli and repel the LNA attack. Similarly, in the lopsided 2020 war over Nagorno-Karabakh, Azerbaijan’s fleet of Turkish TB2s and Israeli drones destroyed Armenian air defenses and precisely attacked rear echelon forces. Observers hailed drones as the pivotal capability responsible for Azerbaijan’s decisive victory.² Now, in the ongoing Ukraine war that began in 2022, drones are playing an unprecedented role. Both Russia and Ukraine have extensively employed military-grade as well as commercial drones for surveillance, artillery fire targeting, and strike missions. Additionally, Ukrainian and Russian forces have made extensive use of kamikaze drones to conduct battlefield precision strikes and attack enemy targets deep behind the front lines.³ Many now see drones as a key capability for achieving victory—or at least avoiding defeat.

These recent conflicts have led to a range of conclusions about the future of warfare. Technology enthusiasts maintain that drones are fundamentally changing the character of war. They argue that drones allow actors to field a relatively cheap air force that is disposable yet able to deliver firepower through mass and resiliency.⁴ There are also hotly contested claims about drones rendering tanks obsolete or replacing existing weapons such as artillery.⁵ Another camp holds that drones are an evolutionary improvement to existing technology. These skeptics argue that air defenses can easily counter drones, which means that uncrewed aircraft are only valuable for countering terrorists and nonstate actors, but not effective against nations with modern militaries.⁶ According to Antonio Calcara and his coauthors, the purported revolutionary effects of drones are “at least premature and probably exaggerated.”⁷

In between these two extremes, there is a third camp that argues that drones have been most effective when used with other capabilities, such as artillery, to rapidly close kill chains.⁸ Military forces undertake a series of actions, called kill chains, which consist of collecting information on the environment, deciding what to do, and then acting.⁹ Typically, kill chains refer to a targeting cycle, which involves finding potential targets, confirming the target, precisely locating it, engaging it with a weapon, and then assessing whether the attack had the desired effect.¹⁰ Armed drones can perform every step in the kill chain themselves, but unarmed drones—that perform the front-end tasks in the kill chain (find, fix, track, and target) and then share this information with artillery units or other drones that fire on or engage the target—have had the biggest impact on the battlefield. In Ukraine, drones allow defenders to quickly detect an attacking force and concentrate fires on it, thereby making offensive maneuvers prohibitively costly.¹¹ These drone debates, however, have not been extensively scrutinized or systematically examined across a range of cases.

The authors conclude that the tempered drone optimists are correct. Drones—particularly when they are paired with other systems—are transforming the battlefield, but this is an evolutionary rather than a revolutionary change. In Ukraine, small drones are making it difficult to mass forces or conduct offensive operations, but their effects remain localized, and most drones remain piloted by humans who control and coordinate their actions. Drones are not substitutes for crewed aircraft, artillery, or missiles, but rather complements to existing weapons. As drones more broadly share real-time information, become more autonomous, and shape doctrine and organizational structures, they may revolutionize warfare, but that day is yet to come.

This report explores the impact drones could have on strategic competition and a high-end conflict with China, and what drones could mean for future warfare. The 2018 National Defense Strategy (NDS) shifted the focus of the U.S. Department of Defense (DoD) from counterterrorism operations in the Middle East to great power competition with China and Russia. It identified China as the priority challenge, tasking the DoD with developing the capabilities and concepts required to stop a Chinese fait accompli attack. The 2022 NDS confirmed that focus, noting that the United States is engaged in a strategic competition with China and identifying Beijing as the Defense Department’s “pacing challenge.”¹²

Drones already play a role in peacetime competition with China today. In peacetime, China has used gray zone tactics involving drones to harass and intimidate other nations in an attempt to expand control over international waters and disputed features in East Asia.¹³ Long loiter times and ranges allow Chinese drones to frequently patrol the skies over the East and South China Seas and, increasingly, near Taiwan.¹⁴ The United States has deployed its large military drones to the Indo-Pacific, establishing an Air Force intelligence, surveillance, and reconnaissance (ISR) drone squadron in Japan and a Marine Corps drone squadron in Hawaii.¹⁵ China and the United States also compete globally, as each seeks to expand its influence over third parties, often through military sales.¹⁶ Drones have become a hot item in the international arms marketplace and an increasingly important diplomatic tool.¹⁷ The United States has been limited in its ability to use drone diplomacy because of its adherence to a Cold War–era arms control agreement, the Missile Technology Control Regime (MTCR). In contrast, China and Turkey, which are not party to the MTCR, have become leading exporters of armed military drones, while Chinese companies simultaneously dominate the commercial drone market.¹⁸

Drones would also impact the outcome of a potential future war between the United States and China. Many believe that drones may help the United States and Taiwan to deter and, if necessary, defeat China in a war.¹⁹ A 2020 RAND Corporation report concludes that hundreds of networked, low-cost drones could guide American long-range antiship missiles toward a Chinese invasion fleet and would be a key capability needed to defeat China and successfully defend Taiwan.²⁰ Similarly, proponents of air denial strategy argue that using “sufficiently large numbers of smaller, cheaper weapons,” including ground-based air defenses and drone swarms, “in a distributed way” would prevent China from gaining air superiority.²¹ Others have focused on the potential for drones to offer the U.S. military affordable mass and thereby offset the quantitative advantage of the Chinese military.²² For instance, in August 2023, Deputy Secretary of Defense Kathleen Hicks announced the replicator initiative, which seeks to produce thousands of “attritable autonomous systems” in less than two years.²³ Replicator aims to apply lessons from Ukraine to the Indo-Pacific theater—mainly, that thousands of cheap drones can help a determined defender mount an effective resistance against a larger aggressor.²⁴ Taiwan also is trying to emulate Ukrainian success by manufacturing thousands of drones as a part of its defensive strategy by mid-2024.²⁵

These initiatives beg several questions: Have the United States and its Indo-Pacific partners learned the right lessons from recent conflicts, including Ukraine? Will the types of drones used in Ukraine and other wars play important roles in a potential U.S.-China war? What roles and missions have drones performed in recent wars, and which tactics have been the most effective? Would these approaches also be useful in a war over Taiwan? Could drones provide the United States and its allies and partners an edge over China and enable a successful defense of Taiwan?

To answer these questions and further explore the roles drones are playing in the competition between the United States and China, the authors took a mixed methods approach. The authors developed a novel dataset of instances of pursuit and actual transfers of military drones between January 1995 and September 2023 and used this dataset to identify trends in drone diplomacy and drone proliferation over the last almost 30 of recent wars in which drones played a significant role: the 2019–2020 battle for Tripoli in the Libyan civil war, the 2020 Nagorno-Karabakh War, and the ongoing war in Ukraine, from February 2022–September 2023.²⁶ From this historical analysis, the authors identified types of drones employed in recent conflicts and considered their effectiveness in different missions and at different parts of various kill chains. Third, to consider the role of drones in a war between the United States and China over Taiwan, the authors conducted a tabletop exercise that sought to develop innovative operational concepts involving drones.

The authors conclude that if China were to invade Taiwan today, Chinese forces are better positioned to leverage drones than the United States or Taiwan. China already has a large and diverse fleet of relatively inexpensive drones that it could employ to find and attack U.S. and Taiwanese forces. This stands in contrast to American and Taiwanese forces, who do not have large inventories of drones or the right mix of drones to successfully defeat a Chinese invasion. The geography of the Indo-Pacific and the distances American forces would need to operate from would put the United States at a disadvantage in a Taiwan scenario. The United States must rapidly acquire longer-range drones with more endurance to close this gap, while developing a layered system of defenses to counter Chinese drones. Taiwan also needs to improve its air defenses and to acquire more short- and medium-range drones across different domains. At the same time, Washington and Taipei need to develop more sophisticated and autonomous drones for the future.

The remainder of this report is divided into four chapters. The first chapter lays out a typology of drones. The second examines how drones have proliferated globally and how the cast of characters has changed along with the drones themselves. Chapter 3 explores how drones have been used in recent conflicts in Libya, Nagorno-Karabakh, and Ukraine and concludes with comparative conclusions from these three case studies. The fourth chapter examines the roles that drones could play in a future war over Taiwan between China and the United States, presenting notional drone and counterdrone operational concepts for each nation’s military. The report concludes with overall findings and recommendations to U.S. and Taiwanese policymakers. The appendix provides more details about the drone pursuit and transfer dataset.