Year in Review – 2021


| Dec 30, 2021

Year in Review

The approach of a new year provides an opportunity to reflect on the past year and to anticipate what the future may hold in the next. In keeping with the tradition of year-in-review surveys, we asked affiliates of the Lieber Institute what they considered were the most notable law of armed conflict developments of 2021. We also asked what legal issues they believed might become prominent in 2022.

Below, Professors Laurie Blank, Eric Jensen, Daphné Richemond-Barak, and Michael Schmitt share their thoughts on the past year. A future post will address some of our affiliates’ predictions for the year ahead.


Laurie Blank

Outer Space Finally Makes the Law of War’s Greatest Hits

The domain of outer space and a growing repertoire of space capabilities have played an essential role in military operations, at least for the United States and many other nations, for at least three decades. But until recently, the public and academic discourses about space law and about the law of war remained almost entirely separate—until 2021, when the topic of military operations in outer space made space law a hot issue for the law of war community, and the law of war a similarly interesting issue for the space law community.

The impending release of at least one, if not two, manuals on the application of international law to military operations in outer space has contributed to a comprehensive and robust exploration of many challenging issues, including the threshold for the use of force and armed attack, the application of the definition of military objective to space objects, and the status and protections of persons in a domain with fluid interplay between military and civilian actors.

One area ripe for further discourse is the protection of civilians in military operations in, through, or from outer space. Protection of civilians has, naturally, been a dominant issue in military operations over the past few decades, with counterinsurgency and other operations in densely populated areas. With outer space, one might imagine a respite from high-intensity civilian protection issues—after all, there are few civilians in outer space (at least for now—the advent of space tourism may bring a change!).

Space operations, however, present a number of interesting issues or complications in the context of targeting. For example, what constitutes a civilian object in outer space, where nearly every object has or can be transformed for a military use. This conflation between military and civilian objects demands nuanced thinking about the definition of military objective, lest everything in outer space become a military objective, drastically reducing protection for civilian and commercial activities in outer space during conflict.

A second question is what constitutes civilian harm in the context of proportionality? To start, perhaps the most important question is which civilians? Space objects can and do provide services to civilians in countries around the world, untethered to the territorial scope of the conflict. Unlike our ordinary conception of civilian harm that tends to be bounded factually by the geographical area of the hostilities, an attack on a space object can cause severe harm to civilians on the other side of the world. Does a proportionality analysis have to consider all civilians anywhere?

Similarly, reverberating effects become not merely a complex issue in certain situations, but an almost automatic issue for any attacks on objects in outer space. How do we assess the effects of space debris or the second- and third-order effects of damage to a satellites or transponders that support emergency disaster relief or severe weather warnings for proportionality purposes?

2021 was a great launch. Going forward, applying the law of war’s core principles to military space operations will continue to demand careful and innovative thinking to ensure fidelity to the law of war’s core goals and principles.


Professor Laurie Blank is a Lieber Senior Fellow and a Clinical Professor of Law at Emory University School of Law. She is also the Director of the Center for International and Comparative Law, and the Director of the International Humanitarian Law Clinic at Emory University School of Law.


Eric Talbot Jensen

The Rise (and Fall) of the Jus Post Bellum

As 2021 dawned, it was apparent that the United States was committed to withdrawing from Afghanistan, even with the new Biden Administration on its way into the Oval Office. Though President Trump’s openly broadcasted timelines adjusted with the new Presidency, the United States was on course for withdrawal and the complete transition of effective, as well as apparent, power to a democratically elected Afghan government. Whatever vestiges of armed conflict that remained in that war-torn country would be passed to the new regime that the United States had unilaterally forced to work with its old (and current) enemy, the Taliban. Of course we all know how that turned out.

In a matter of less than a month, the Taliban orchestrated an almost completely unopposed return to power and whatever nation-building efforts had been made in the previous 20 years were quickly and completely undone. Afghanistan’s Ambassador to the UN, Nasir Ahmad Andisha, described the situation as a “total reversal of two decades of advances.”

Certainly the United States has gained and will continue to gain some benefits, even if only temporary, from the two decades of blood and treasure expended in Afghanistan. But the rapid return to the previous regime after a full generation of military and political investment should cause us all to reflect on the vastly understudied aspect of the LOAC known as the jus post bellum—the law once armed conflict has ended. In addition to the obligations of an occupier, which the United States is adept at passing on to regimes it quickly puts in place, what legal obligations does a nation have after twenty years of armed conflict in a country? Must an occupier stay until the populace has changed sufficiently to be able to resist a return to a regime that ignores basic human rights and refuses to uphold international legal obligations? Does a former occupier have a legal obligation to provide military capability and equipment sufficient for the remaining regime to resist the onslaught of insurgents that would undo democratic and legal reforms to government and society? What legal (and moral) obligations does an evacuating power have to safeguard (and potentially relocate) the tens of thousands of employees, contractors, and supporters on its way out?

While 2021 might be remembered for the close of U.S. military involvement in Afghanistan and the subsequent disastrous return to Taliban rule with its concurrent human rights abuses, it will hopefully also invoke a review of the jus post bellum and the legal obligations that do and should apply in the aftermath of military operations.


Eric Talbot Jensen is a Lieber Senior Fellow and Professor of Law at Brigham Young University.


Daphné Richemond-Barak

Advance Warning and the Al-Jalaa Tower

IHL reached a very low point in May 2021 when it was suggested that a legitimate target could somehow lose its status as a military objective following an evacuation conducted in response to the law’s advance warning provisions. The claim was made during Operation Guardian of the Walls, the latest military confrontation between Hamas and Israel. As part of the operation, Israel targeted the Al-Jalaa Tower in Gaza because it contained military assets belonging to the intelligence offices of Hamas and housed the organization’s R&D unit. This unit was reportedly used to sabotage and disrupt the actions of the Israel Defense Forces and jam Israeli communications equipment.

The claim that a military objective could lose its status in the wake of an advance warning—though made in the limited context of the Israeli-Palestinian conflict—undermines the law of armed conflict, its application in a wide range of conflicts, and the incentives that it creates for belligerents to provide advance warning. Many leading scholars, including Michael Schmitt, Brian Cox, and Amichai Cohen and Yuval Shany, have taken issue with it.

That advance warning could alter the nature of a target and render a strike unlawful also carries great danger for IHL compliance. States might grow more wary of advance warnings—which, by nature, already often compromise the effectiveness of strikes by forfeiting the element of surprise or increasing the exposure of forces to attacks. The law itself contemplates these downsides when it states that such warnings must be given “unless circumstances do not permit.” Some margin of discretion is built into the law, which could easily be exploited by States if advance warning were to carry the risk of rendering a strike unlawful. Such an interpretation of the law could well end up producing a situation where, from a belligerent’s standpoint, the cost of providing advance warning could ultimately outweigh its advantage.

Pressured to include the strike against the Al-Jalaa Tower as part of the Palestine investigation, the ICC should be careful what it wishes for. Advance warning plays a critical role in ensuring the protection of the civilian population in time of war, and it should not be undermined.


Dr. Daphné Richemond-Barak is a Lieber Senior Fellow and  Assistant Professor in the Lauder School of Government, Diplomacy and Strategy at IDC Herzliya.


Michael N. Schmitt

IHL’s Applicability in Cyberspace: Reaching Consensus in 2021

2021 was a memorable year in international humanitarian law (IHL) for many reasons, not least of which was the Taliban victory in the longest war in our history. But beyond the hot battlefield, the year marked an important milestone in discussions over the applicability of IHL in cyberspace. The international community has finally reached consensus over what any IHL expert would deem self-evident—IHL governs cyber operations during armed conflicts.

Serious consideration of whether, and if so how, international law applies to cyberspace began in earnest in the late 1990s with a memorandum from the DoD’s Office of General Counsel (“An Assessment of International Legal Issues in Information Operations”). It concluded,

There are novel features of information operations that will require expansion and interpretation of the established principles of the law of the war. Nevertheless, the outcome of this process of extrapolation appears to be reasonably predictable. The law of war is probably the single area of international law in which current legal obligations can be applied with the greatest confidence to information operations.

The topic remained dormant in the years that followed, as attention was diverted by the 9/11 attacks and the conflicts they ignited. However, the 2007 cyber operations against NATO-member Estonia and a 2008 war between Georgia and Russia, which included disruptive cyber operations against civilian and military targets in the former, refocused attention back on conflict in the cyber domain.

In 2009, the newly formed NATO Cooperative Cyber Defence Centre of Excellence launched a project to consider the application of international law during cyber conflict. The International Group of Experts (IGE) that produced the resulting 2013 Tallinn Manual on the International Law Applicable to Cyber Warfare came to much the same conclusion the DoD OGC had a dozen years earlier, as did a different IGE in its 2017 Tallinn Manual 2.0. IHL applies directly and comprehensively to cyber operations, although some accommodation for the unique aspects of such operations is necessary.

This is not to say that no questions remain. For instance, under what circumstances can a cyber operation initiate an armed conflict? How do the rules regarding attacks apply, or not, when a cyber operation is non-destructive and non-injurious, but highly disruptive? Does the prohibition on attacking civilian objects apply to operations that alter or delete data?

But until 2017, these and other open issues appeared not to belie the fact that cyber operations during an armed conflict were subject to the same IHL rules, albeit with some adjustment for circumstances, as kinetic operations. This was the conclusion of NATO and the EU; the ICRC;  and many States, including the United StatesNetherlandsUnited Kingdom, and Australia. All have reiterated this position repeatedly.

Perhaps most importantly, in its 2015 report, the fourth UN Group of Governmental Experts on Developments in the Field of Information and Telecommunications in the Context of International Security (GGE), which included the UN Security Council’s permanent members, noted the importance of international legal principles, including, “where applicable, the principles of humanity, necessity, proportionality and distinction.” The UN General Assembly subsequently endorsed the report. As these are IHL principles, there appeared, on the surface, to be unanimity on the application of IHL in the cyber context.

And then the fifth GGE convened from 2016-2017. Russia, China, Cuba, and a number of other nations represented in the group opposed text dealing with countermeasures, express mention of self-defense, and inclusion of the term “international humanitarian law.” The later point (and that on self-defense) felt like normative regression given the implicit reference to IHL in the 2015 report.  But Cuba explained, “the supposed applicability in the context of ICT of the principles of international law… would legitimize a scenario of war and military actions in the context of ICT.” The assertion was, of course, badly flawed as a matter of law. But there we were.

Which brings us to this year. The issue of IHL and cyber operations loomed large during the two UN efforts to continue to identify cyber norms that completed their work in 2021. Although the Open-Ended Working Group (OEWG) that was open to all UN members issued a report that did not reference IHL, the Chair’s Summary observed,

international humanitarian law reduces risks and potential harm to both civilians and civilian objects as well as combatants in the context of an armed conflict. At the same time, States underscored that international humanitarian law neither encourages militarization nor legitimizes resort to conflict in any domain.

And the sixth GGE became the first in the series to acknowledge IHL’s applicability to cyber operations explicitly. Its consensus report settled the matter.

The Group noted that international humanitarian law applies only in situations of armed conflict. It recalls the established international legal principles including, where applicable, the principles of humanity, necessity, proportionality and distinction that were noted in the 2015 report. The Group recognised the need for further study on how and when these principles apply to the use of ICTs [information and communications technologies] by States and underscored that recalling these principles by no means legitimizes or encourages conflict.

Russia and China’s membership in the GGE, and therefore their agreement with the consensus report, signals that IHL’s applicability is a dead issue; attention must now turn to unsettled issues surrounding how it applies in the cyber context. Numerous statements made by States both outside the GGE (see, e.g., France, Finland, Israel) and in the Compendium of State views on international law annexed to the report exemplify this reality.

2021 was noteworthy for confirming what was evident to IHL experts from the very beginning — that IHL is a body of law flexible enough to accommodate new methods and means of warfare. With the unfortunate earlier confusion on the matter behind us, States can now turn to the real issue at hand, the nuances of its applicability in cyberspace.


Michael N. Schmitt is the G. Norman Lieber Distinguished Scholar at the United States Military Academy. He is also Professor of Public International Law at the University of Reading, Strauss Center Distinguished Scholar and Visiting Professor of Law at the University of Texas, and Professor Emeritus at the United States Naval War College.