In an effort to persuade Delhi to downgrade its defence ties with Russia, the United States has exerted significant pressure on on India targeting the country’s plan to acquire the S-400 long range air defence platform. Aside from threatening the country with economic sanctions under the Countering America’s Adversaries through Sanctions Act (CAATSA), the U.S. has also indicated that it will cease to provide India with a number of highly sought after defence products including Predator drones should India purchase the S-400. Most recently, according to Indian sources, the United States has considered offering India its own long range air defence platform, the Terminal High Altitude Air Defence (THAAD) system, should Delhi abandon its plans to acquire the S-400. While THAAD costs considerably more than the Russian system, the success of the new U.S. strategy relies heavily on the weapons systems’ viability as a replacement for the S-400.
One of the primary reasons why India sought the Russian S-400, a platform designed with advanced anti stealth capabilities to counter American fighters such as the F-22 Raptor, was to protect the country’s airspace against the growing Chinese stealth fighter fleet. Alongside the Chinese J-20 air superiority fighter and upcoming J-31 medium fighter, H-20 bomber, and several cutting edge stealth drones, China is also reportedly aiding Pakistan on India’s Western border to develop its own light stealth fighter – under a joint fifth generation fighter program similar to the fourth generation JF-17. Unlike the S-400, THAAD not only lacks counter stealth capabilities – but it also lacks anti aircraft capabilities entirely and is designed solely to intercept enemy ballistic missiles. This seriously limits its usefulness to India.
While the S-400 is capable of deploying five different missile types, from the 40km range 9M96E specialised counter stealth platform to the extreme range 40N6 which can target enemy aircraft with precision at ranges of up to 400km at hypersonic speeds, THAAD by contrast deploys only a single missile type. This means that unlike the S-400, the American system is incapable of providing multi layered air defence of Indian airspace. In addition, with the S-400 is highly compatible with existing Indian air defence platforms such as the S-300, Tor and Strela, THAAD will be unable to work as part of a network with these Russian and Soviet made systems. Missiles launched by the THAAD notably carry no warheads, and are restricted to ranges of approximately 200km – half the range of the S-400. This means that not only are the weapons more expensive, but more batteries will be needed to cover the area of India’s borders. Unlike the S-400, THAAD will be unable to engage hostile targets deep into enemy airspace – with an S-400 able to engage hostile targets across Pakistan and much of China.
An analysis of THAAD’s capabilities indicate that the system is likely poorly suited to India’s defence needs, and a poor substitute to the S-400. As its name suggests, the missile system is designed to intercept missiles at high altitudes which while valuable for the defence of the U.S. mainland from intercontinental range ballistic missiles, will have few applications against short ranged missiles deployed by China and Pakistan. Alongside their fighter and bomber fleets, these missiles will be able to pass through a THAAD defence shield unimpeded. Unlike the highly versatile S-400, THAAD is restricted to targeting enemy missiles at altitudes of 40-160km, while against short and intermediate missiles such as the Pakistani Ghauri and Chinese Dongfeng 12 the system would be effectively useless. This was attested to by numerous experts including former U.S. Chief of Naval Operations science advisor Theodore Postol, who noted that against such missiles “the THAAD defence can be expected to provide … no useful defence capability.” The historically poor performance of U.S. made air defences, both in testing and in combat against relatively basic pre-Vietnam War era missiles, is another factor which must be taken into account which indicates that the reliability of THAAD may well also be highly questionable.
Based on an analysis of its capabilities therefore, the THAAD system will be a poor choice for India – an air defence platform wholly incapable of replacing the S-400 not only in its ability to target advanced enemy stealth aircraft – but in its ability to provide any defence against enemy fighters, bombers and short and intermediate range ballistic missiles whatsoever. These platforms will comprise the vast majority of attacks on Indian territory in the event of war. Indeed, given the extremely limited threat posted by high altitude intercontinental ballistic missiles to India, platforms highly unlikely to be used given the country’s proximity to its adversaries, the uses for the THAAD system remain extremely limited. Ultimately India has great need for the S-400 to retain parity with its neighbours in light of the growing sophistication of their aerial warfare and missile capabilities, and the United States and its Western allies, who have historically invested little in air defence compared to Russia and the Soviet Union, are poorly placed to provide a platform with comparable capabilities.