Uncertainty continues as to whether China is selling weapons to Russia for use in the Ukraine war. After President Xi Jinping’s visit to his Russian counterpart Vladimir Putin in March 2023, leaked US intelligence documents showed China had approved the provision of weapons to Russia disguised as civilian items. This was met with a clear statement from China’s foreign minister that “China will not provide weapons to relevant parties of the conflict”. Meanwhile, the Chinese Defense Minister paid a visit to Russian military officials, while Ukraine said it was increasingly finding Chinese weapon components on the battlefield.

It is well known that Russia has solicited China’s military support for use in Ukraine. Soon after the invasion of 24 February 2022, Russia asked China for surface-to-air missiles, drones, intelligence-related equipment and armoured and logistics vehicles. So far, China has seemed unwilling to do this, at least not openly. Doing so would almost certainly trigger Western economic sanctions and would put the Chinese State in violation of international law and the Arms Trade Treaty. But these would not be the only legal consequences. Xi and other Chinese political leaders could be individually responsible as accomplices to Russian war crimes under the Rome Statute of the International Criminal Court (ICC).

Under international criminal law, complicity is about assisting in the commission of a crime by another person. The accomplice can help the perpetrator of a crime in various ways, for example by providing goods – in this case military assistance – that contribute to the commission of a crime. Criminal liability generally requires that the aid granted has some effect on the crime committed and that the accomplice provided their support and assistance when they knew, or should have known, that it would facilitate the commission of the crime.

Regarding accomplice liability for war crimes, it is currently well known, including to Xi, that there is overwhelming evidence that Russian armed forces have committed war crimes on a massive scale in Ukraine. After more than a year of war, there are extensive allegations of the killing, torture and sexual and gender based violence against civilians. If Xi starts supplying weapons knowing of Russia’s track-record in Ukraine, he would be complicit in future commission of war crimes. Given the scale of the crimes, it would be inevitable that weapons supplied by China would not only be used directly in combat in Ukraine, but would also contribute to the commission of war crimes.

Xi would be unable to credibly claim he is unaware of UN findings on war crimes or reasonably rely on any Russian assurances that Chinese weapons would not be used in operations where crimes are being committed on the battlefield. In our view, Xi's complicity under international criminal law would not require evidence to prove that a weapon supplied by China has actually been used in a specific offence, such as the murder of a specific civilian

or prisoner of war. It would suffice, in our view, that significiant Chinese military support has facilitated the commission of war crimes by Russia more broadly, as would certainly be the case with the nature and scope of military support that has been requested by Russia.

There is a plausible legal argument that the ICC could hold Chinese leaders responsible as accomplices to Russian war crimes (and possibly crimes of aggression and genocide, although the legal case for complicity in those crimes is more complex, and we do not address it here). Accomplice liability for war crimes may also exist under national criminal justice systems, but Xi and certain other high-ranking Chinese officials would enjoy immunities in foreign national prosecutions, as long as they are in office. By contrast, the ICC would have jurisdiction to prosecute Xi, since his immunities would not apply, at least based on previous ICC case law on head of state immunities and bearing in mind the fact that a warrant for the arrest of Putin, also a leader of a state that is not party to the Rome Statute, was issued on 17 March 2023.

Even with a strong legal basis for Xi’s individual complicity in war crimes, an ICC prosecution would not materialize easily. The ICC has shown its commitment to firm and energetic action on Ukraine through the issuance of the Putin arrest warrant. But for the time being, the ICC is expected to focus on the most senior military and political perpetrators, rather than accomplices from third-states. This lack of enforcement at the ICC makes it even more important that Xi receives a clear signal –internationally– that arms deliveries to Putin will not only lead to sanctions, but make Xi –personally– an accomplice under international criminal law.

A final point: the West supplies weapons to Ukraine on a large scale and the UN Commission of Inquiry has identified isolated incidents of war crimes committed by Ukrainian forces. Would this make Western leaders, such as Scholz, Sunak or Biden, equally complicit in war crimes that have been –or will be– committed by Ukraine? At present this is not the case. There is no evidence that Ukraine commits war crimes on a significant scale or structurally. As a result, the West’s supply of arms does not amount to criminal facilitation of the commission of incidental war crimes by Ukraine. This could change if Ukrainian armed forces start committing war crimes on a large scale and if Western leaders, with knowledge thereof, were to continue to supply weapons.