Indian Defence Review

S-400

On 14 November 2021, Russian news agencies, citing Dmitry Shugayev, head of the Russian military cooperation agency, reported that Russia has started delivery of S-400 Triumf missile system to India.^[1] According to a news report the S-400 “would be first deployed at a location close to the Western border from where it can tackle threats from both parts of Western and Northern borders with Pakistan and China”.^[2]

S-400 Triumf is arguably the most advance surface to air missile system and is in service with only a handful of countries including Russia and China. It is considered superior to the Patriot, or any other Western missile system in service today. An upgrade of the S-300 missile system, it first went into service in 2007 in Russia. Impressed with its capabilities,SiemonWezeman of Stockholm International Peace Research Institute (SIPRI) called it “is among the most advanced air defence systems available”.^[3]

An S-400 unit comprises two batteries, each with a command-and-control system, one surveillance radar, one engagement radar, and four launch trucks that are termed ‘transporter–erector–launcher’.  The S-400 is equipped with four different types of missiles: short-range 9M96E (40km), medium-range 9M96E2 (120km), long-range 48N6 (250km), and the very long-range 40N6E (400km). The system operates in the following way:

Long-range surveillance radar tracks object and relays information to com­mand vehicle for target assessment.

After the target is identified, missile launch is ordered by the command vehicle.

The launch vehicle which is placed in the best position gets the launch data and releases the missile.

The missile is guided toward the target with the help of the engagement radar.

The S-400 Triumf air defence system is unlike any other air defence missile system in the world and has been called a game-changer. With the maximum effective range of up to 400 Km, it can track 100 airborne targets and engage six of them simultaneously and has the capability to counter low-observable aircraft and precision-guided munitions. Its deployment by Russia after Turkey’s shoot-down of a Russian Su-24 FENCER airplane near the Syria border on24 November 2015 compelled Turkey to pause its air operations and reportedly impacted the execution of U.S. and coalition air operations in the region because of Triumf’s considerable reach and lethality. It has rightly been called the ‘most dangerous’ operationally deployed modern long-range SAM in the world.^[4]

It can engage a wide range of targets, including stealth aircraft and cruise missiles with its missiles that can travel at speeds of up to Mach 14 or 17,000 kmph. It can also destroy aircraft or missiles flying five metres above ground level by targeting them from above. S-400 can engage ballistic missiles and function as an anti-ballistic missile (ABM) system. This gives it the capability to provide an umbrella against adversary’s missiles in case of a nuclear war.

Anti-Stealth and Anti-Jamming Capability

The S 400 Systems is equipped with 91N6E panoramic radar with a claimed range of 150 km against stealth targets. The maximum targeting ranges (detection ranges are wider) are:

• For a ballistic target (speed of 4800 m/s and a RCS of 0.4 square metres): 230 km
• For a target with RCS of 4 square metres: 390 km
• For targeting of strategic-bomber sized types: 570 km

It also has 96L6 high-altitude detector radar and equipment operates independently of the 96L6E low-level radar detector. The 96L6E2 export version can track a maximum of 100 targets and can perform the functions of a command post for  S-400 Systems.  The S-400 is equipped with sophisticated electronic warfare systems employing  countermeasures like rapid frequency-hopping and agile beam-steering. It also employs methods that reportedly help detect stealth aircraft using radars like the Nebo-M that is designed to track and engage stealth aircraft at tactically meaningful distances.

Effect of deployment of S-400 by India

China has deployed two S-400 at Nyingchi and Hotan though she is expected to deploy the larger share of its S-400 against Taiwan and possible areas of conflict with US. Indian S-400 would be deployed on the other hand to cover the western and northern borders with Pakistan and China. This means that the effect of this deployment would be on our immediate neighbours and not against any distant adversary. And this has different implications altogether.

The range of S-400 against aircraft operating at medium or high altitudes is so great that it can threaten aircraft in neighboring countries within their own air space. This capability alone raises the risk of operating such expensive aircraft anywhere near a deployed S-400 system. It forces the adversary to alter their procedures to guide manned and unmanned aircraft flying within range of the S-400. This is a direct effect that will alter the powerplay between the adversaries.

The deployment also means that the adversaries will have to accept a higher loss risk when carrying out operations in the areas covered by the S-400. Though the conventional mix of stealth, electronic attack, decoys, and radar-homing missiles will continue to be relied on to degrade the S-400, the traditional methods will most likely be ineffective to counter the air defence system. If the adversary operates outside the envelope of the S-400 system, air missions will not likely be worth conducting because so few airborne capabilities can operate effectively at so distant a range.^[5]

As per one commentator, the early failure of Prithvi Air Defence (PAD) may have influenced India’s decision to go in for the S-400 and itis expected to add to the existing Indian Ballistic Missile Defence (BMD) capability and act as a shield against ballistic missiles providing an umbrella against Pakistani or Chinese missiles in case of a nuclear war. The missile system is, therefore, a force multiplier that can dramatically influence the outcome of a war.^[6]

 Just as the Chinese S-400 have altered the balance of power in the Taiwan Straits, now, with the deployment of S-400 the rules of the game in the sub-continent are also likely to be changed. With its long range the  S-400 would virtually cover most of Pakistan which means Pakistani fighters would become extremely vulnerable, tilting all battlefield equations against the PAF.^[7] As an article in Indian Defence Review pointed out “the system can literally take the war into the enemy’s airspace. For instance, an S-400 based at Halwara air base, can bring down an F-16 flying over Lahore in just 34 seconds, giving the Pakistani pilot no time to say his prayers.”^[8]

This was stated quite explicitly by the former Air Chief Dhanaoas he said  that “the purpose of the S-400 and Rafale is to hit Pakistani aircraft inside Pakistani air space and not when they come inside Indian territory”.^[9]

Limitations and Vulnerabilities

Its stated capabilities and effective range notwithstanding, an air defence weapon is only as effective as the surveillance and C2 network for without timely detection and identification of targets, the ability to shoot down hostiles is only of academic interest. The same limitation is applicable for S-400 Triumf as the field of view for the integral search and fire control radar is limited to the horizon of the earth. To enhance the capability, search radars need to be put on tall masts to better see over the horizon or use the airborne warning and control aircraft systems (AWACS), or on stationary tethered balloons known as aerostats.

As the S-400 class of missile systems perform the anti-ballistic missile role (ABM) as well, it needs to be closely integrated with the AWACS aircraft. Depending on the number of S-400’s and the types of targets they are expected to defend there may be a need to expand the size of the existing AWACS fleet to provide nearly continuous coverage to the-400 sites.

The primary threat to S-400 is from the low-altitude cruise missiles and drones as exemplified by the drone attacks on the Saudi oil facilities and the ballistic missile attack on an American airfield located in Iraq. The challenge in detecting low-altitude slow targets even by advanced radars like Nebo-M was well illustrated by the successful taking out of the same radar in Azerbaijan by a Turkish Baryatkar TB2 drone.^[10]

The OODA loop – observe, orient, decide and act – critical for decision-making is all the more important to exploit the full capabilities of S-400. There are two aspects to this. One, if a target is to be engaged at its optimum range, the time available to decide on engaging it is critical. A decision not taken in-time may render the system ineffective. Second, the vulnerability of the OODA loop itself (i.e. the sub-systems that carry out the OODA functions). This vulnerability has often been flagged as Indian AD remains vulnerable due to possible hacking of the OODA loop by the adversaries.^[11] 

Why S-400 is more than a defensive weapon system

Defensive weapons are traditionally defined as those that have a limited range and destruction area and for that reason can (essentially) only be used on one’s own territory; offensive weapons systems are all the others.Air defence weapons, guns and missiles, were developed to counter hostile and defend our assets from damage. Long range air defence missiles were first developed by Soviet Union (now Russia) to destroy hostile aerial targets well before they endangered the homeland by intercepting the incoming targets over the ‘buffer zone’ available to the west. The adversary was not so much impacted as it operated well outside the range of these long-range missiles. The use of these missiles by a country against a geographically contiguous adversary has different implications as the air space of the adversary can be covered even when the missiles are deployed well within own territory. It is this capability that puts apart the S-400 from other air defence missiles and makes it more than just a defensive missile system.

It can also be understood by looking at the definition of ‘air defence’. AD is”all measures designed to nullify or reduce the effectiveness of hostile air action”.^[12]It includes surface based, subsurface, and air-based weapon systems, associated sensor systems, command and control arrangements, and passive measures. The air defence weapons range from long range surface to air missiles to guns for close defence. 

If the capabilities of S-400 of destroying enemy targets at 400 kilometers away are seen in context of the definition of ‘air defence’, it is apparent that its capabilities go beyond the limited scope of ‘nullifying or reducing’ effectiveness of hostile air action as a S-400 with its long range can effectively take on targets in enemy territory, interdict enemy air and thus has an inherent offensive capability.

It is not the first missile system to threaten and engage hostile targets hundreds of kilometres away. Decades earlier, SA-5 Gammon (S-200) was deployed in 1966 and with its 200 km range was the one of the early long-range AD missile systems in service. It was used by Libya in the 1980s and more recently by Syria making it the first AD missile system that could engage and threaten hostile aircraft over a hundred kilometres away. It was followed by the S-300 and its clones produced by China. Yet S-400 is in a different category altogether due to its increased lethality thus making it more of an offensive than a defensive weapon.

Conclusion

China already has  S-400 missile system in its inventory and had deployed its S-400 squadrons at Hotan air base in Xinjiang and Nyingchi air base in Tibet, just across Ladakh and Arunachal Pradesh respectively. This has reportedly “forced the national security planners into a rethink about air defence and counter-measures.”^[13] While the counter-measures being planned and considered by India are not being discussed here, it is interesting to take a look at how Pakistan views the induction of S-400 by India. An article in Air Force Magazine of the United States Air Force covers the subject in elaborate details and offers a number of options to be exercised.

Induction of S-400, use of electronic warfare, development of ICBM with Multiple Independent Re-entry Vehicle(MIRV) capability and use of cruise missiles and drone swarms are some of the options discussed and it needs to be observed what all options are exercised by our neighbour to the west.

It needs to be remembered that the capabilities of the S-400 and its effect on the powerplay between the opposing air forces makes it a prime target. It is vulnerable to both hard and soft kills and even while it can take on hostile targets, it also needs to be defended from hostile acts. The uniformed wise men will undoubtedly consider all options and take the right decision and it will be interesting to keep a track of the developments in this sphere.