Both US lawmakers and Ukrainian officials have raised concerns regarding the final destination of weapons donated and sold to Ukraine. Ukraine has historically had one of the largest black markets for arms in Europe, with around 300,000 small arms and light weapons reported lost or stolen during the Russian invasion of Crimea between 2013 and 2015. This number is small compared to the estimated US$32 billion lost in Ukrainian military equipment stolen and sold on the black market between 1992 and 1998. NATO nations have spent US$40 billion sending weapons to Ukraine since the war started, and the extent to which equipment remains solely in control of the Ukrainian military is unclear. This uncertainty raises questions about what is happening to the mass amounts of weapons the United States and NATO allies have distributed and sold to Ukraine in the past two years.
There are also questions about the legality of the types of weapons being sold and provided to Ukraine by the United States (cluster bombs) and the United Kingdom (depleted uranium rounds), as well as some of the weapons reportedly deployed by Russia, including chloropicrin, phosphorous bombs, and other chemical weapons. Both Russia and Ukraine have also violated the 1997 Anti-Personnel Landmines Convention; anti-personnel landmines, which remain hidden underground and active, endanger aid workers, civilians, and other noncombatants.
The illicit nature of banned weapons and the potential for weaponry theft and circulation on the black market raise genuine concerns about the security of arms sales to Ukraine. These two problems, which continue to plague lawmakers in Washington, have been exacerbated by the perpetuation of the war in Ukraine.
The Illegal Movement of Weapons
Weaponry Theft in Ukraine: Reality or Russian Disinformation?
The invasion of Ukraine has led to a larger quantity of weapons entering Europe, and thus a greater possibility for weapons to go missing. Since 2022, there have been sporadic reports of small and large arms being stolen in Ukraine. In early 2022, a Russian-led criminal organization operating in Ukraine reportedly stole at least one grenade launcher, a machine gun, and over 1,000 rounds of ammunition to sabotage and destabilize Ukraine’s efforts to secure the region. Although it is difficult to confirm when and where weapons are stolen, the sheer scale of weapon transfers means that it is highly likely that some weapons will go missing over the course of the conflict.
However, when examining the extent to which illicit weapons are being used or sold in Ukraine, it is important to acknowledge the massive amount of Russian disinformation about these weapons. Russia has been working within the United Nations to spread disinformation about the state of weapons being sold to Ukraine by the United States and other Western nations. Reports about Finnish gangsters, French rioters, Nigerian fighters, and Mexican cartels gaining weapons—like rifles and grenade launchers—from Ukraine have all been debunked as Russian propaganda attempting to sway the United States and NATO allies to decrease arms transfers. Russia is actively trying to disincentivize US support for Kyiv, which necessitates caution when discussing illicit weapons trading in Europe.
End-Use Monitoring of Weapons by the United States and Ukraine
Ukraine has also consistently released information about the state of weaponry in the country and allowed for US end-use monitoring through the State Department or the Department of Defense. However, while these actions evidence transparency, US end-use monitoring is relatively ineffective in Ukraine due to the frequent movement of weapons along front lines. The current US end-use monitoring program focuses on Man-Portable Air Defense Systems and Anti-Tank/All-purpose Tactical Guided Missiles because of the classified information used to build those weapons. Contrarily, monitoring efforts have paid little attention to small arms and light weapons, yet those are the weapons more likely to be stolen by criminal organizations in Ukraine. In January 2024, the US military admitted that it had failed to effectively track over US$1 billion worth of small and light arms. The US military also stated that it could not maintain an accurate serial-number inventory of those weapons. Therefore, while there had been no reports of the weapons being stolen, it was impossible for the Department of Defense to fully determine the endpoint of the weapons.
The United States has also shifted the majority of responsibility for end-use monitoring onto Ukraine, due to the difficulties of managing large-scale weapons transfers. However, Ukrainian officials have also struggled to track weapons movements, and oversight failures have had lethal consequences. Oleksandra Ustinova—a former anti-corruption activist in Ukraine who now monitors foreign arms transfers to Ukraine—stated: “We’ve literally had people die because stuff was left behind, and they came back to get it, and were killed.”
The Deployment of Illegal Weapons in the Russo-Ukrainian War
Cluster Munitions
Along with clearly illegal transfers of weapons within and beyond Ukraine, there are murkier questions about transfers of illegal types of weapons from the United States to Ukraine. The most significant example of illegal weapons used in Ukraine has been cluster munitions. Both Ukrainian and Russian forces have utilized these weapons. Cluster munition usage is banned by the Convention on Cluster Munitions, which 123 countries—excluding Russia, Ukraine, and the United States—have signed. Several European supporters of the agreement—including Spain and the United Kingdom—have criticized President Biden’s decision to send cluster munitions to Ukraine on humanitarian grounds. The US Export Control Act states that the United States can only transfer cluster munitions that “after arming do not result in more than one percent unexploded ordnance across the range of intended operational environments.” Biden’s exports of cluster munitions violated this rule. However, he argued that extreme circumstances and Russia’s usage of the weapons justified the decision.
Chemical Weapons
In addition to cluster munitions, Russia has actively been deploying chemical weapons prohibited by international law. According to an official statement by Ukraine's General Staff on December 27, 2023, Russia had carried out 81 chemical attacks in Ukraine in December 2023 alone. It is unclear whether the substances inside these weapons are chemicals like mustard gas or ‘just’ tear gas that is burning at an incredibly high temperature of 650 degrees Celsius. However, even if the chemicals being used are ‘only’ tear gas, usage still violates international law. These violations have pushed Ukraine to violate international law to match the scale of violence inflicted by Russia. According to the Institute for the Study of War, Russia resorted to using World War I chemical weapons—such as chloropicrin, a compound used in the agricultural industry—in January 2024. A spokesperson for the Tavria Ukrainian military group stated that “Russian forces had been using K-51 grenades with chloropicrin in their attacks on Kyiv's positions.” These usages of chemical weapons demonstrate Russia’s violations of international law.
Russia also accused Ukraine of using chemical weapons in the eastern Ukrainian towns of Soledar and Bakhmut without any evidence. The Ukrainian public affairs office stated that "the enemy's accusations of the use of chemical weapons by units of the Armed Forces of Ukraine are untrue" and that Ukraine did not use chemical weapons "anywhere...at any time." Russia’s accusations could reflect attempts to legitimize its own usage of chemical agents and spread propaganda to Russian and Ukrainian citizens about the plight of Russian troops.
Looking Ahead: The Geopolitical Consequences of Illicit Transfers and Illegal Weapons
This spread of Russian propaganda—combined with the transfer of questionably legal weapons and lots of smaller munitions—can be geopolitically destabilizing. For example, there have been concerns that Ukraine will use US tanks to cross the Russian border, which would place the United States in a de facto state of war with Russia. In the context of cluster munitions, some fear that Ukrainian usage would cause Russia to escalate to other chemical and larger-impact weapons. There is also fear that, if Russia continues to use chemical weapons, Ukraine may escalate usage as well.
The extent to which arms are being illegally trafficked once arriving in Ukraine is overstated by Russian media sources, but the US and Ukrainian governments are straining to track weapons to ensure that none go missing. The usage of cluster munitions by both Moscow and Kyiv and Russia’s usage of chemical weapons, however, are not being overstated. The deployment of these weapons is particularly concerning, given Washington’s difficulties tracking weapons. These weapons present real threats of conflict escalation and great harm to civilian populations in both Ukraine and Russia. While small arms falling into criminal groups' hands may have peripheral consequences, a world in which these actors can obtain cluster munitions and chemical weapons would have catastrophic consequences for stability beyond the Russo-Ukrainian War. End-use monitoring of all these weapons needs to be a major focus to prevent dangerous weapons from falling into the wrong hands.
