Over the past year, cluster munitions—weapons banned by a majority of the world’s countries—have killed or injured hundreds of civilians in Ukraine. Their use, which began the first day of Russia’s full-scale invasion, is also creating a deadly legacy of explosive remnants that will endanger the local population for months and even years to come. Russian armed forces are responsible for the vast majority of attacks with cluster munitions, but Ukrainian forces appear to have used them several times.
Cluster munitions are large weapons that contain dozens or hundreds of smaller weapons known as submunitions and do not discriminate between soldiers and civilians. They harm civilians at the time of an attack, particularly when used in populated areas, because their submunitions spread over a wide area. To make matters worse, many of the submunitions do not explode on impact but remain a threat like landmines until they are disturbed.
I have advocated against cluster munitions, among other inhumane weapons, for more than two decades as a field researcher and lawyer. Knowing my background, my Harvard Law students often ask if recent events have made me discouraged about my work.
I am, of course, deeply concerned about the use and effects of cluster munitions in Ukraine. But I have maintained my faith in international law. This body of law establishes legal rules regarding the relations between countries and countries’ treatment of individuals, including during times of armed conflict. I have seen that, while not a panacea, international law can serve as a powerful tool to make the world safer for civilians.
I first encountered cluster munitions when I joined Human Rights Watch after graduating from law school. My start date was to have been September 12, 2001, but the 9/11 attacks postponed it for a week. Six months later, I was in Afghanistan with a team investigating civilian casualties from US airstrikes. My part of the project was to document the harm caused by the US use of cluster munitions.
We interviewed victims of cluster bomb strikes and the unexploded submunitions they left behind and presented our report and its findings to a United Nations disarmament conference. In addition to highlighting the effects of these weapons on civilians, we proposed creation of a new treaty to restrict the use of cluster munitions. An international treaty would establish clear rules that would bind every country that joined it and could even influence those that did not.
Six years later, continued calls for new international law, bolstered by documentation of cluster munition use in Iraq in 2003 and Lebanon in 2006, drove countries to act. I saw firsthand how far such law could go when I participated in the negotiations that produced a treaty called the Convention on Cluster Munitions.
Proponents of this treaty adopted a people-centered approach to governing the weapons, known as “humanitarian disarmament.” It focuses on addressing arms-inflicted human suffering rather than on advancing national security. By emphasizing humanitarian concerns, the approach made it easier for countries to transcend national interests and work together.
In this case, the Cluster Munition Coalition, a global coalition of nongovernmental organizations, which included Human Rights Watch, partnered with supportive governments and international organizations. Although some major military powers, including the US, Russia, and China, did not participate, more than two-thirds of the users and producers of cluster munitions were involved in the process.
Informed by the humanitarian approach to disarmament, the convention includes measures to both prevent future civilian harm and address the harm that has already occurred. It prohibits the use, production, transfer, and stockpiling of cluster munitions. It also requires countries that have joined the convention to destroy their stockpiles of these weapons, clear areas contaminated with unexploded submunitions, and provide assistance to victims.
When I attended the signing ceremony for the convention in Oslo in December 2008, I was surprised to hear more-experienced disarmament advocates caution that “now the real work begins.” While fact-based calls for new international law can spur countries to act and negotiations can create legal obligations, a treaty must also be put into effect.
In this implementation work, the Convention on Cluster Munitions again offers an example of the influence of international law.
Today, the convention has 111 states parties—countries that have agreed to be legally bound by its provisions. An additional 13 countries have signed the convention, a step toward completely accepting it, and may not act against its object and purpose. None of these countries has violated the core prohibitions.
Along with its prohibitions, the convention’s positive obligations are making a difference. According to the Cluster Munition Monitor 2022 report, since the convention was adopted in 2008, 1.5 million cluster munitions and 178 million submunitions have been destroyed, saving countless civilian lives. At least nine affected states parties have finished clearing their contaminated areas, and assistance for victims has improved, although more work remains to be done in these areas.
The convention’s stigmatization of cluster munitions is having an impact beyond its states parties. Since its adoption, the United States, for example, has launched only one isolated cluster munition strike, in 2009 in Yemen. The last US company to manufacture cluster munitions ceased production of them in 2016.
The Convention on Cluster Munitions has also informed responses to the war in Ukraine. Although neither Russia nor Ukraine has joined the convention, opponents of cluster munitions, including me, have used it as a tool to generate international condemnation of the use of the weapons. Fifteen states parties, the NATO secretary- general, the UN high commissioner for human rights, and the European Union condemned the attacks within the first month of the war.
In addition, the convention has impeded the proliferation of cluster munitions to Ukraine. It explicitly prohibits states parties from transferring the weapons to anyone, and, to date, political pressure stemming from the convention seems to have deterred any Ukrainian ally from sending them.
The convention has not been enough to stop the use of cluster munitions in this armed conflict, but that is not a reason to give up on international law. While some people still commit murder, those violations have not led society to reject the laws that prohibit it.
Instead, we must urge more countries to join the Convention on Cluster Munitions and draw on its provisions in our efforts to protect civilians from this unacceptable weapon of war.