U.S. Sources Claim China Supply Russia with Su-35 and S-400 Parts to Fight Ukraine: How Credible is the Story?

Since the outbreak of the Russian-Ukrainian War there have been wide ranging allegations from a number of Western sources claiming that various third parties are supplying Russia with armaments or dual use products to bolster its war effort. Some claims such as those of Iranian drone sales have had more evidence behind them, while others such as North Korean artillery shell transfers being are certain. These allegations are made as the Western world has provided massive support to the Ukrainian government worth tens of billions of dollars, ranging from battle tanks and guided artillery rounds to the deployment of hundreds of NATO satellites and over 300 Royal Marines to the battlefront and setting up of a massive “stealth network” by U.S. intelligence agencies organise the war effort. While the Western world has been isolated in siding against Russia, with only three non-Western countries joining Western economic sanctions, any third party support for the Russian war effort will have amounted to a tiny fraction of the backing the West is providing to Ukraine. Where signs of overseas support for Russia remain scarce, perhaps the most unusual claim was made by the Wall Street Journal on February 4 stating that China was not only providing a wide range of dual use goods, but also military equipment to the Russian Military. These allegations cited records from the Washington-based nonprofit C4ADS.

Among the equipment provided, the Journal notably alleged that China was supplying spare parts for S-400 air defence systems and Su-35 fighters to Russia – both assets China ordered in 2015 in small numbers for its own armed forces. “On Oct. 24, Chinese state-owned aircraft firm AVIC International Holding Corp. shipped to AO Kret, a subsidiary of sanctioned government-owned defence giant Rostec, $1.2 million worth of parts for Su-35 jet fighters… parts sent on Oct. 4 [went] to Russia’s sanctioned state-owned missile-manufacturer Almaz Antey for use on the 96L6E mobile radar unit. Russia uses the radar to detect enemy jet fighter, missiles and drones as part of its S-400 antiaircraft missile system being used in Ukraine, according to arms analysts. The Russian firm didn’t respond to requests for comment,” it claimed. Although these are two of very few modern high end weapons systems operated by both China and Russia, the credibility of claims that China would supply spare parts to Russia remains in serious question. 

China currently fields just one and two respective regiments’ worth of the Su-35 and S-400, which are widely thought to have been acquired primarily as part of technology transfer deals rather than to genuinely transform Chinese aerial warfare capabilities. No agreements on license production of the systems were ever reached, and spare parts China has are not known to exceed those that came with the original contracts. Thus not only would supplying Russia seriously undermine China’s ability to operate much valued Russian systems, particularly the S-400s which provide a number of unique capabilities, but the small quantities available draws into question how useful such supplies would actually be. While there have long been calls in the West to seek to find premises for imposition of secondary economic sanctions on China for its continuance of normal economic ties with Russia, in defiance of Western efforts to place maximum pressure on the Russian economy, sales of Su-35 or S-400 parts remain highly unlikely. A more viable narrative may well be a claim that India is supplying parts for Russia’s Su-30SM fighters, since it deploys over twice the number of closely related Su-30MKI fighters and built the large majority of them and their spare parts domestically – providing grounds for both sides to actually benefit from such a deal. The fact that India is not seen as a challenger to Western power, and therefore is not a desired target of secondary sanctions, means there is little incentive to fabricate such allegations. 

A key factor undermining claims that Russia would need to import Su-35 or S-400 spare parts from China, despite the very small quantities China has, is that not only have Russian inventories of the same systems seen very little erosion in the war so far, in contrast to other kinds of assets such as tanks and tactical ballistic missiles, but Russia has also continued to export S-400s and Su-35s indicating a lack of parts shortages for either. Russia has significantly accelerated deliveries of S-400s to India, with a third unit beginning deliveries in January 2023 and two more set to be delivered later in the year – all while the Russian Military continues to enlarge its own inventory. The Su-35, meanwhile, has seen an export contract signed with Iran with deliveries of 24 airframes expected by March 2024. Iranian pilots have been reported by U.S. sources to have already begun training in Russia accordingly. Thus should Russia have grave enough shortages of the Su-35 and S-400 that it would need to buy back it spare parts from China, it would hardly be able to export significant quantities of these systems with associated spare parts simultaneously. If anything, the war in Ukraine has raised concerns in Beijing that the U.S. and its allies may seek to escalate conflict in East Asia in future, and could well lead China to seek to increase its stockpiles of Su-35 and S-400 spare parts – which can likely be paid for in local currencies under new Sino-Russian agreements on the dedollarisation of trade.