S-400: How India’s New Russian Air Defence System Affects The Strategic Game In South Asia 

In November 2015, Turkey shot down a Russian Su-24 fighter over Syria, dangerously exacerbating tensions between Moscow and the West. Just days later, Russia responded to the provocation by deploying the S-400, its newest missile-defence system, in Syria. The move pushed the Turkish Air Force out of Syrian airspace while forcing the United States (US) to change tack. Just three years down the line, Turkey is at loggerheads with the US to buy S-400s from Russia and Washington is trying to prevent the acquisition and has retaliated by blocking the transfer of the Lockheed Martin F-35 fighters to Ankara.

Earlier today, India signed a deal with Russia for the purchase of S-400 systems. When the system takes up duty defending the Indian skies in the next few years, it may similarly force India’s adversaries to change tactics.

To begin with, what is the S-400 system?

The S-400 is the world’s most potent operationally deployed modern long-range surface-to-air missile system. It is capable of shooting down incoming aerial threats such as aircraft, drones, and cruise and ballistic missiles, using four different missiles – the very long range 40N6E-series, the long range 48N6, the medium range 9m96e2 and the short range 9m96e.

The 40N6E missile has an estimated operational range of 400 km and is capable of reaching a maximum altitude of up to 185 km. Multiple reports have said that the missile is also capable of exo-atmospheric interception of intermediate-range ballistic missile warheads at a time when they begin to reenter the atmosphere, also called the terminal phase of the missile trajectory. While the 48N6 missile can hit objects 250 km away, the 9m96e2 and the 9m96e missiles can strike targets at a distance of 120 and 40 km, respectively.

The Patriot missile defence system used by the United States and its North Atlantic Treaty Organisation allies, in comparison, supports only one interceptor missile with a range of 96 km.

Despite its medium range, the 9m96e2 missile is often refereed to as the ‘jewel’ of the S-400 system. Flying at Mach 15 (15 times the speed of sound or 18,500 km per hour) and manoeuvring up to 20g, the missile is capable of engaging targets as low as five metres off the ground. It can knock out penetrating aircraft and cruise missiles that may be flying just a few meters above the ground, a tactic often used to avoid detection by enemy radars in hostile territory.

It doesn't end here. The acquisition and engagement radars of the S-400 system, which track enemy objects and guide a missile towards it, respectively, come with countermeasures against jamming (emission of radio frequency signals to interfere with the operation of a radar and render it ineffective).

Additionally, Russia’s Nebo-M system can also be integrated with the S-400 to detect stealth fighters. However, it is not known if India is buying this system and other optional equipment such as Cheese Board 3D surveillance and tracking radar.

Does China having the system before India makes it less effective?

The fact that China, which has started taking deliveries of its first system under a deal signed in 2014, will have this capability deployed before India has prompted many to question the utility of the system and its place in India’s scheme of things. The question is fair, but it is based on a misconceived notion that Beijing will bring to bear all its military assets along the border with India. Although it has a disputed border with India, China’s main focus has remained the security of its population and industrial centres along its eastern coast, where it faces threats from the US. This is where China is expected to deploy its S-400 systems.

The deployment of Terminal High-Altitude Area Defence (THAAD) anti-ballistic missile system by the US in South Korea in 2017 to defend against North Korean missiles has upset China. After the system was operationally deployed in 2017, China had contended that it would undermine its nuclear deterrent capability by degrading its ability to carry out a nuclear second strike in a war against the US. Beijing had also hinted at improving its anti-missile capabilities in response, and the S-400 systems that it is acquiring, could be used for this purpose.

Despite their mobility, the systems are unlikely to be placed by China along its border with India in the event of a conflict for fear of exposing its coastal flank to attacks. The mountainous terrain, too, would make its deployment difficult. Therefore, China’s western flank is not likely to be under the cover of the S-400s, especially in case of a swift, limited and localised conflict.

All that said, it should be noted that China’s western flank will not lie defenceless. China has around 15 divisions of the S-400's predecessor system, the S-300. At least one S-300 system has been deployed in Tibet since 2010, giving China limited missile defence capability. China has also developed surface-to-air missile systems such as HQ-16, HQ-12 and HQ-9, which have been deployed in Tibet.

The number of S-400 systems India will acquire and how it plans to use them is not precisely known. Reports suggest New Delhi could procure up to five systems and may deploy at least two on the border with China. These would, in theory, block incoming missiles and aircraft from the Chinese mainland.

With the rough terrain on the border making movement of large-scale ground forces difficult, any major Chinese attack would come with a large aerial offensive that would include missiles, fighter jets and drones. With India using S-400s along the border, it would be better placed to neutralise these threats than China, which would use less-effective systems to tackle Indian attacks. Thus, the S-400s will give India some advantage over China and acts as a major deterrent.

How will it affect the matrix with Pakistan?

India may deploy at least three of its S-400 systems along the border with Pakistan, mostly to strike down incoming ballistic missiles. Pakistan’s territory will be swept by the S-400’s jamming-resistant radar. Given its lack of depth, any missile fired from Pakistan would come into the 600 km tracking range of the S-400 system almost immediately. This would give the system the longest possible time to respond and strike down the incoming threat.

The same is true for any fighter jet, unmanned aerial vehicle and cruise missile that Pakistan may try to use against India in the event of a conflict.

Rakesh Krishnan Simha explains this using a hypothetical scenario:

“A posse of F-16 jet fighters takes off from the Pakistan Air Force (PAF) base in Sargodha. Approximately 300 km east, at the Adampur air force base, an Indian S-400 system picks up these aircraft instantly. The radar lock unnerves the F-16 pilots and they peel further west – away from the battery’s range. While taking evasive action the PAF jets have to be careful not to stray into Afghanistan – which is increasingly hostile towards Islamabad – or Iran. The Pakistani pilots, however, realise trespass is the least of their problems. As the F-16s arrive over Balochistan – the furthest they can get away from the Indian border – they are tracked by another S-400 battery stationed near the Jodhpur air force base 527 km away.The S-400 systems are routinely scanning the airspace around them in a 360 degree sweep, but the PAF pilots are on the verge of panic. Between the overlapping coverage by India’s multiple S-400 battalions stationed along the border, PAF aircraft can run but not hide. This is the fishbowl effect – the feeling of being observed from all sides.”

Pakistan’s plan to use battlefield nuclear weapons during a conflict will also be affected by the deployment of these systems. Military planners in Pakistan have often contended that they would use battlefield weapons on their soil to halt Indian thrust, bringing down the threshold of a nuclear war. These weapons, if fired, can theoretically be detected by the S-400 system and destroyed swiftly.

To penetrate the S-400 cover, Pakistan would need to use a large number of missiles, fighters or drones (to overwhelm the system’s tracking capability). This would prove prohibitively expensive for Pakistan.

Therefore, the deployment of the S-400 systems would dramatically affect Pakistan’s strategy against India, forcing it to change its tactics. Some of these effects are already visible, with Pakistan rushing to induct Chinese surface-to-air missile systems to strengthen its defences.

That said, all air defence systems around the world, including the S-400, remain largely untested in real battlefield environments. These systems aren’t 100 per cent effective, and it is unclear as to whether they can track and eliminate all incoming threats.

An earlier version of this piece was published as ‘How India’s new Russian air defence system will force adversaries to change tactics’ on 26 January, 2018.