Are cracks appearing in Russia-China ties after the People’s Liberation Army’s border skirmishes with India and an espionage case involving a senior Russian official?

Moscow is Beijing’s most important de facto ally as both face a more belligerent Washington. Chinese President Xi Jinping has enjoyed tight ties with his Russian counterpart Vladimir Putin as both authoritarian leaders seek to stay in power and advance their geostrategic interests.

Yet the suspicious suspension of Moscow’s shipment of its ace S-400 Triumf mobile air defence missile systems since at least February may signal a breakdown in the camaraderie.

Chinese news portals including NetEase and Sohu have reported a delay in the delivery of S-400 mobile missiles to the Chinese military. They cited the Chinese Defence Ministry and Beijing’s ambassador extraordinary and plenipotentiary to Moscow Zhang Hanhui as blaming the Covid-19 epidemic for the delay.

Chinese state media has maintained that China-Russia military ties and arms deals will remain impervious to the global pandemic and the West’s supposed plot to sow dissension. S-400 anti-aircraft missiles, known for having the longest range of their kind worldwide, have figured large in Beijing’s big-ticket Russian arms deals. The S-400 is reportedly able to engage thirty-six targets simultaneously.

That capability would be crucial as Beijing seeks to ramp up military pressure on Taiwan’s Pacific-facing littoral waters from the mainland’s south-eastern Fujian province.

In 2014, Beijing became the first foreign buyer of the hypersonic S-400 that was then offered at US$300 million per launch unit. The system’s long-range would allow the PLA to target Taiwan proper as well as its fighter jets including F-16s deployed along the island’s Pacific coast.

Beijing’s acquisition of the S-400, initially consisting of six batteries, also allows the PLA to cover the disputed Senkaku Islands, aka Diaoyu, from its northern province of Shandong. Japan also claims the islands. In 2018, the PLA successfully launched and hit a supersonic target projectile with the S-400 during a drill in China’s far west.

NetEase reported that Beijing has expressed its understanding after the S-400 production by Fakel Machine-Building Design Bureau was “hobbled” by Covid-19 outbreaks in Russia. Yet the coronavirus may not be the only factor jamming the gears of the high-stakes military cooperation between the two nations.

A union-busting espionage case involving China in Russia was recently revealed by Indian news agency ANI. It claimed that Russia’s FSB nabbed Valery Mitko, director of a social science institute in St Petersburg affiliated with the Russian government, in February on grounds of treason.

Charges levelled at Mitko include feeding Chinese agents intelligence about Russian sonar and submarine detection technologies while he was a visiting scholar at the Dalian Maritime University in north-eastern China back in 2016.

Hong Kong’s Ming Pao daily also cited sources within China that Beijing’s embassy in Moscow had a dedicated office “guiding” the regiment of Chinese students, visiting scholars and contractors in the county to glean classified information about the Russian military and aerospace and nuclear sectors.

Moscow has also reportedly bridled at Beijing’s covert copying and drive to ratchet up indigenous research and development of key defence parts and technologies to ease its reliance on Russian products. Chinese orders have long been a lifeline for ailing Russian defence suppliers.

The most salient case of Beijing’s endeavour is the J-20 fighter. Chengdu Aircraft Industrial Group, manufacturer of the fifth-generation stealth jet, has been trialling homemade engines, including the Emei that is modelled after a Russian design, to propel the most advanced warplane of the Chinese Air Force. The J-20 previously relied on Russia’s Salyut AL-31 turbofan engine to get airborne and break the sound barrier.

While Moscow’s ties with Beijing come under apparent strain, Russia’s Defence Minister Sergey Shoygu has reportedly reached an agreement with his Indian counterpart Rajnath Singh to fast-track the production and delivery of the five S-400 sets India bought for $5.5 billion in 2018. The first batch will be delivered by 2021.

Moscow has also bagged big orders from New Delhi while the latter is on a spending spree on equipment from overseas to replenish its arsenal. Russian military firms have emerged as a beneficiary of India’s standoff with China along their disputed Himalayan border, which descended into crude violence in mid-June, resulting in the deaths of at least 20 Indian soldiers and an unknown toll on the Chinese side.

New Delhi’s $2.4 billion shopping list with Moscow includes 21 MiG-29 fighters, 12 Su-30 jets, upgrades to 59 existing MiG-29s as well as more than 200 air-to-air missiles.

The big-ticket arms deals have incensed many Chinese netizens, with a tirade of posts on WeChat and Weibo lambasting Russia’s “perfidious profiteering” from China’s tensions with India.

“Don’t expect any backing from Russia when China is in a war, but beware of a stab in the back from Putin,” read one post.

For now, Chinese state media has opted to play down Moscow’s military dealings with New Delhi. Chinese Foreign Ministry spokesperson Wang Wenbin said last week that this year’s reciprocal state visits by Chinese and Russian leaders would go ahead as scheduled.