Thanks for continuing on with this series of posts with me. In Part I, I explained what cluster munitions are and why the Biden administration decided to give them to Ukraine. I addressed their failure rate – noting the Biden administration claims the transferred munitions will have a no greater than 2.35% dud rate and opponents’ reasonable concerns of a 10-20% dud rate in actual field use. I described the absolute prohibitions of use and transfer under the Cluster Ban Treaty as well as the governing Geneva Convention limitations on indiscriminate and disproportionate attacks. I concluded that one’s assessment of whether cluster mine use is per se unlawful for non-Cluster Mine Ban Treaty parties depends on one’s beliefs about whether the dud rate is ever permissibly low enough. Whether Ukraine’s specific cluster mine use will be lawful turns on whether you believe their assurances about how and under what conditions they will be used as well as dud rates. In Part II, I explained why the transfer raises no domestic law problem for the United States nor for Cluster Mine Ban Treaty parties, as no current transfer and use is envisioned for treaty parties allied with Ukraine.
But in Part III, I’ll explain that even in the absence of a clear international law violation (presuming you don’t view cluster munition use as a per se violation of international law), this transfer still implicates the norm against cluster mine use. I’ll begin with a brief description of pre-transfer norm and then explain why I think the transfer is particularly problematic. I’ll conclude in Part IV with a laundry list of ways the U.S., Ukraine, and Cluster Mine Ban Treaty parties can reinforce either the norm against cluster munitions or the more general norm of civilian protections after this transfer.
I. Cluster Mines Norms Before the U.S. Transfer to Ukraine
In order to get a sense of the norm against cluster mine use and transfer, I think it is helpful to look at the behavior of both treaty parties and non-treaty parties. While one set of states is legally prohibited from using or transferring and the other set of states has no such prohibition, high treaty compliance helps inform the existence of a norm. The reason I reference a norm rather than custom is the absence of near-universal and uniform conduct among states and the lack of a belief by non-treaty states that international law required non-use and non-transfer (for non-treaty parties).
A. Treaty Parties’ Compliance
For the 110 parties to the Cluster Mine Ban Treaty, overall compliance has been quite high. The Cluster Ban Treaty monitor has no reported use by any state parties since the treaty went into effect. Of the 17 state parties that had produced cluster munitions prior to the treaty, all have ceased production, including South Africa and the UK. Compliance with the stockpile destruction requirement has also been quite high, with 99% of declared stockpiles destroyed and only four state parties still working toward completion. The destruction of stockpiles and cessation of production helps lock in compliance, as it becomes more costly to restart use.
While initial support for the treaty was high, new memberships slowed around 2016, with zero new memberships in 2021. But among the ratifications, there are several countries that have used cluster munitions prior to treaty membership as well as countries at high risk for future conflict, such as Nigeria. In other words, the treaty can boast members that might actually have used cluster mines in the absence of the treaty’s existence.
What about the cluster munition use, transfer, and stockpiles of non-treaty parties? Since the treaty entered into force in 2010, cluster munitions have been used in a handful of states—Azerbaijan, Cambodia, Libya, South Sudan, Syria, Ukraine, and Yemen. The confirmed users include Libya, Saudi Arabia, Syria, Ukraine, and Russia, as well as a few non-state actors and either South Sudan or Uganda, both of whom disclaim use. Notably, despite active military engagements, neither the United States nor Israel has used cluster munitions since the treaty went into effect, though both maintain that international law would permit them to do so. So while significant munition use has occurred after the treaty, it is largely conducted by pariah states we would not expect to be constrained by international weapons norms, while non-signatory democracies were largely forgoing use. Of course, as mentioned in prior posts, Ukraine was using cluster munitions prior to the U.S. transfer, but such use was relatively limited (by access rather than by choice) and relatively unpublicized other than a Human Rights Watch report.
Meanwhile, many non-party states, including the U.S., were phasing cluster munitions out of service. For instance, the U.S. had altered weapon systems so they would use only single-munition warheads rather than cluster warheads. The U.S. had also been moving in the direction of stockpile destruction. Prior to the Ukraine transfer, it awarded a 28 million dollar contract for the destruction of at least a significant portion of the nearly six million cluster munition stockpile. (For a more detailed discussion of U.S. policy, see my prior post).
As for production and transfer, that too has declined for non-treaty parties, but 16 non-party states still produce or reserve the right to transfer cluster munitions. Until 2022, none had transferred cluster munitions to Ukraine, but Turkey—not the United States—broke that seal. At least 15 states continued to transfer cluster munitions to at least 60 other countries after the Cluster Mine Ban Treaty went into force.
Many non-treaty parties also have pledged unilateral limitations. For instance, Estonia, Finland, Poland, and Romania (not coincidentally all states that border Russia) have pledged to limit cluster munition use to their own territories. I discussed the extensive U.S. unilateral limitations on use and transfer in the last post.
II. Cluster Mine Norm and the Ukraine War
As discussed in my first post, Russia has extensively used cluster munitions in Ukraine. But because Russia is an international law pariah, its use alone does not, in my opinion, unravel the norm against use. Rather Russia was the example of the rogue state that makes clear why we have such a norm in the first place. It used high-dud-rate munitions and targeted civilians, and it had no intention of marking or debombing the land it struck. Both Cluster Mine Ban Treaty parties and non-parties alike condemned Russia’s use of cluster munitions in Ukraine. So while Russia’s use was highly problematic and profoundly unlawful, it was not a departure from expected practice prior to the conflict.
But now the U.S. has transferred cluster munitions to Ukraine, drawing great international and domestic consternation. While this is a major decision, it is worth pointing out that the U.S. declined to provide cluster munitions in its first 41 military aid packages starting in August 2021. It convinced South Korea, a country reluctant to provide lethal assistance, to send ammunition to Ukraine in May 2023 rather than itself send cluster munitions. To me, this speaks to the strength of the norm against use. The U.S. went to extensive lengths to avoid the decision to transfer munitions and I believe that is in no small part due to the Cluster Mine Ban Treaty. Take the counter factual: if this decision had come up before the existence of the Cluster Mine Ban Treaty (and even more so, before the existence of the landmine ban treaty), the yes would likely have been reached much faster. In other words, the U.S. viewed this decision as a high- rather than low-cost decision, and the emerging international norm was a significant part of what raised the costs. (The U.S. could have been troubled by the possibility of civilian casualties even in the absence of the Cluster Mine Ban Treaty, but the push for the treaty massively raised the knowledge and profile of such casualties).
But of course, now that the U.S. has transferred and Ukraine is using these munitions on a large scale, the worry is that not only might Ukrainian civilians be harmed, but also other countries might use this as justification for their own use. In other words, if this was a hard case justifying use, then why not the next conflict in which the state and the military can make a persuasive case that it is a key moment in the conflict or they are running low on conventional weapons or that it is only to be used to help repel invaders? And once persuasive cases start being made, why won’t that unravel support for the travel and lead to use in even non-persuasive cases? This has always been the line of the ban treaty advocates—once you acknowledge one state of exception, then other exceptional cases will surely follow. And regardless of the legitimacy of an exception from a single state’s point of view, the international community should not view any case as legitimate or persuasive. So in Part IV, I’ll discuss what I think the United States, Ukraine, and Cluster Ban Treaty parties can do to shore up the norm against cluster munition use and more generally the emerging norms to protect civilians.