As India considers its threat environment, it must consider not just ballistic missiles, but also cruise missiles, such as those that might potentially be launched from Pakistan or China. These latter are far more difficult to detect and intercept than are ballistic missiles.
A cruise missile has been defined as a “weapon which automatically flies an essentially horizontal cruise flight profile for most of the duration of its flight between launch and its terminal trajectory to impact.” Land-attack cruise missiles further complicate the task of any defense system, since they can be terrain hugging and can also fly a circuitous trajectory.
In particular, Pakistan’s Babur and Raad cruise missiles represent a threat to India. Meanwhile, China’s cruise missile arsenal include the Seersucker, Silkworm, the ground launched DH-10 and the air-launched CJ-10, C-101 and HN series, to name a few. Some of China’s missiles are nuclear capable.
As it considers these weapons, one of the key questions that confronts New Delhi is whether it should opt solely for a cruise missile defense or also adopt a “deterrence by punishment” posture with the help of its own cruise missile arsenal. While a cruise missile defense could possibly intercept a subsonic cruise missile, it may be difficult to intercept supersonic cruise missiles and it is virtually impossible to intercept hypersonic cruise missiles. Although at present neither Pakistan nor China possess a hypersonic cruise missile, that could very well change. China already has supersonic cruise missiles such as the C-101 and C-301. Pakistan has also acquired the new CM-400 AKG, a supersonic cruise missile claimed to be hard to intercept because of its velocity.
For its part, India is currently working on a ballistic missile defense. India’s Defence Research and Development Organisation is developing a defense system with two layers, with Advanced Air Defence (AAD) as the first layer and the two-stage Prithvi Air Defence (PAD) as the second layer. However, neither PAD nor AAD would be able to intercept cruise missiles.
Using anti-air missiles of various ranges, it may still be possible to intercept supersonic anti-ship cruise missiles (although intercepting land-attack missiles remains a Herculean task). France, for instance, has been able to intercept supersonic anti-ship cruise missiles using its Principal Anti-Air Missile System. For it to replicate the feat, India would need an effective command, control, communication, intelligence, surveillance and reconnaissance system. Even with that, intercepting hypersonic cruise missiles would very likely remain unrealistic. Moreover, missiles with low radar signatures make the job of any air or missile defense system that much more difficult. Any surface-to-air missiles used would need to be highly sophisticated, with high-power large aperture radars, although even that might not be enough to intercept incoming threats. India could hope to defeat air-launched cruise missiles by destroying the aircraft that carry them. However, both Pakistan and China are developing stealth technology that could make it difficult for India to locate and destroy the aircraft before they fire.
All of which means that while defense by denial is an important approach, India ought also to consider another form of defense. Specifically, it must concentrate on its own hypersonic cruise missiles. To maximize deterrence, its cruise missile arsenal should also be nuclear capable. Deterrence by punishment is a useful option when defense in general may not be sufficiently robust to counter the threat, and nuclear-capable cruise missiles would be as effective in that respect as nuclear-capable ballistic missiles. Indeed, the moment a missile becomes nuclear capable, it has value as deterrence.
In fact, next-generation cruise missiles for India and for other countries are likely not only to be faster, but will also be able to carry non-nuclear warheads that are equally cataclysmic, like directed energy weapons, such as electromagnetic pulse (EMP) weapons that could disable command, control and communication systems. A high-speed, sophisticated cruise missile carrying such a deadly warhead would surely give an adversary pause.
Already, India’s BrahMos supersonic cruise missile is capable of evading any missile defense system in the world. There are also plans to develop a hypersonic version. Either version is likely to defeat any defense system it counters. The next step would be for the missiles to be nuclear capable, making them a deterrence against not only conventional cruise missile attacks, but also against nuclear strikes using cruise missiles or even ballistic missiles.
Debalina Ghoshal is an Associate Fellow at the Centre for Air Power Studies.