The Law of Armed Conflict in 2040

by | May 27, 2022

LOAC 2040

In the summer of 2020, the Lieber Institute team and I convened a workshop at West Point titled “LOAC 2040.” We invited a group of law of armed conflict (LOAC) scholars and practitioners from around the world, and with a range of perspectives, to consider how that body of law and institutions for creating, interpreting, and enforcing it might look two decades ahead—as well as what opportunities may exist to influence it in that time.

The output of that workshop—The Future Law of Armed Conflict, which I co-edited with LTC Thomas Oakley of the West Point Law Department—is now available from Oxford University Press. It is the latest volume in the Lieber Studies series under the general editorship of Professors Michael Schmitt and Sean Watts.

As I write in the new volume’s introductory chapter (a version of which is available here):

Warfare is changing—and rapidly. New technologies, new geopolitical alignments, new interests and vulnerabilities, and other developments are changing how, why, and by whom conflict will be waged. Just as militaries must plan ahead for an environment in which threats, alliances, capabilities, and even the domains in which they fight will differ from today, they must plan for international legal constraints that may differ, too.

The workshop identified several broad and overlapping categories of change especially relevant to development of LOAC.

    • Novel technology—such as digital systems, artificial intelligence, and hypersonic weapons—is altering military capabilities and vulnerabilities.
    • New and changing domains of conflict—especially cyber and space, and related patterns of “hybrid warfare” involving large-scale information operations—are changing where and how conflicts will be waged.
    • Evolving roles of actors besides States—especially non-State (or loosely affiliated) armed groups, civil society organizations, private corporations, and processes of legal decision-making—are changing as well.
    • Shifting geopolitical realities—such as the rise of China and the proliferation of weapons of mass destruction—are altering strategic calculi and the distribution of power and influence.

The chapters of the book are arranged roughly around these overlapping categories (see here for the table of contents). Their subjects complement well a recent U.S. Department of Defense emphasis on preparing for high-intensity combat operations in the wake of decades of operations focused on counterterrorism and counterinsurgency operations.

To help frame the discussion, the LOAC 2040 workshop included remarks by U.S. Under Secretary of the Army James E. McPherson, who spoke about some of the challenges U.S. defense planners face in preparing for these rapid developments, including vast zones of uncertainty. A major theme of the workshop discussions, however, was that none of these developments listed above is entirely new; aspects of them have been around for decades, though many of them are accelerating. Therefore, the workshop on future LOAC also featured a keynote address by Sir Adam Roberts. That lecture was developed into the book’s opening chapter, in which Roberts urges caution, based on past experience, in trying to predict what future warfare will look like. He also derives from that experience a set of principles to guide efforts at revising or adapting LOAC to meet future conditions, and these ideas run through many of the chapters that follow. This volume does not aim to lay out a single prediction of the future. Rather, it seeks to lay out some alternative, possible futures and raises big questions and issues that are likely to emerge.

On the whole, for example, contributors see new binding, global treaties in this area as unlikely. Some of the chapters are optimistic that new challenges and gaps can be partially addressed through interpretation of existing treaties and customary law, or by supplementing extant law with additional nonbinding agreements. Other contributors are skeptical, though, that interpretations among powerful States will converge. New challenges are unlikely to break the system, but they will likely bend many parts of it.

There are many reasons why these chapters focus on adapting existing law rather than anticipating new treaty law. As mentioned above, many challenges for the LOAC that are often referred to as “new” are not really so new. They are extensions of old challenges, such as applying longstanding targeting law principles to critical infrastructure that serves both military and civilian purposes. International negotiations are always slow, but technological change is accelerating—and in ways that are hard to forecast. Powerful States are reluctant to bind themselves amid differing or uncertain strategic interests. This last point could change dramatically in the event of a major catastrophe, such as a crippling cyberattack or a highly destructive war involving powerful States—prospects that suddenly seem more likely after Russia’s recent invasion of Ukraine.

On the whole, this is a book about legal adaptation. The authors bring to their chapters a wide range of professional and normative perspectives. They agree, however, that LOAC must continue to adapt if it is to retain its vitality.


Matthew C. Waxman is the Liviu Librescu Professor of Law and the faculty chair of the National Security Law Program at Columbia School of Law.