Russian weapons are creating a headache for the US as it looks for partners to counter China

• The US has sought to improve its relationship with countries in Asia to counter China's rising influence.
• India has been a major target of that effort, but New Delhi's purchase of major Russian weapons may complicate the US's engagement.

US efforts to build closer ties with India face a test later this year, when New Delhi is set to receive the S-400, a Russian-made air-defense system that the US has already sanctioned other countries for buying.

India will get its first S-400 set by the end of 2021, India's ambassador to Russia said at the end of April, according to Russian state media. New Delhi announced its intention to buy the S-400 in 2015 and signed a contract worth more than $5 billion for five regiment-size sets in 2018.

The S-400 - which Russia says can destroy aircraft, cruise, and ballistic missiles, and hypersonic weapons - is set to arrive as India is increasingly focused on countering a Chinese military that fields sophisticated aircraft and long-range missiles.

A deadly clash on their disputed border in the Himalayas in June 2020, the first in decades, prompted Indian Defense Minister Rajnath Singh to urge Moscow to speed up the delivery.

The sale has been a sticking point for the US. The Trump administration sanctioned China for purchasing the S-400 in late 2018 and then sanctioned Turkey for buying it in December 2020.

Russia has been a major arms supplier to India for decades. Those sales have declined in recent years, but India still uses many Russian weapons, such as fighter jets and warships, and relies on Moscow to maintain them.

The Biden administration hasn't taken a public position on sanctions for that purchase. Defense Secretary Lloyd Austin discussed the sale with his Indian counterpart in March but said sanctions weren't mentioned.

"We certainly urge all our allies and partners to move away from ... that [Russian equipment] and really avoid any kind of acquisitions that would trigger sanctions on our behalf," Austin said in New Delhi on March 20.

"There has been no delivery of an S-400 system, and so ... the issue of sanctions is not one that's been discussed," Austin added. "But we did address with the [Indian] minister of defense the issue of the S-400."

The Defense Department has not had "any additional conversations with India about this planned acquisition" since Austin's visit, a department spokesman told Insider, adding that the Pentagon is focused on assisting India with a COVID-19 breakout that is one of the worst in the world.

Strategic autonomy

US-India relations have been ascendant, due in large part to shared concern about China's growing influence. The two countries' military cooperation has increased, but India has sought to maintain its ties with Russia, a reflection of its desire for "strategic autonomy."

While US sanctions over the S-400 weren't discussed in Austin's meeting, they are seen as likely to undercut Washington's efforts to work closer with New Delhi.

"That's going to really undermine the relationship, and we need to avoid that," Joe Felter, deputy assistant secretary of defense for South Asia from 2017 to 2019, said at a recent panel event hosted by the Joint Special Operations University.

"But India needs to play ball with us and understand that ... buying US equipment is not only investment in quality defense equipment," Felter added. "It signals who you want to build your relationship with."

Indian officials, however, may bristle at sanctions, seeing them as interference in their affairs and disregard for the billions India has already spent on US weapons, while remaining undeterred from purchasing Russian arms. (India already had to navigate US sanctions to pay for the S-400.)

"For the next couple of years I don't think there is going to be an attempt at jettisoning that relationship [with Russia] from the Indian side," Nandan Unnikrishnan, a distinguished fellow at Observer Research Foundation in New Delhi, said at a recent Wilson Center event.

While Indian defense spending is likely to continue declining and be spread among more suppliers, "India is going to buy some of the necessities it has from the Russians because it's not available anywhere else," Unnikrishnan added.

The 2017 US law that requires sanctions also contains a waiver provision. US officials have reportedly told India it is unlikely to get a waiver, but at least one US lawmaker has called on Biden to grant one.

While the Biden administration has said little about the issue, "signaling on the strategic relationship is broadly positive," according to Richard Rossow, Wadhwani Chair in US-India Policy Studies at the Center for Strategic and International Studies.

Austin's visit to India was his first foreign trip, and it came a few days after Biden himself joined his Indian, Australian, and Japanese counterparts at the first meeting of leaders of "the Quad," an informal grouping focused on cooperation in the Indo-Pacific region.

"Considering our overall awareness that India plans to onboard the S-400 missile-defense system at some point over the next two years, these are key signals," Rossow said.