India’s sea leg of nuclear deterrence is operational. It has test-launched a long-range ballistic missile from its indigenous nuclear-powered submarine, bringing the majority of the area in the Chinese mainland within its striking range.
Contrary to widespread belief, India’s second indigenously built nuclear-powered ballistic submarine, INS Arighat, is equipped with a K-4 submarine-launched ballistic missile with a range of 3,500 kilometers. The missile was test-fired on November 27 from the newly commissioned submarine in the Bay of Bengal.
While the Indian government has not officially announced anything, a NOTAM has been issued to the flights to refrain from entering the 3490-kilometer corridor. No word has been given if the missiles met all the perimeters of a successful test, but this is the first time that the missile has been launched from a submarine. So far, it has been test-fired only from a submersible pontoon.
India’s first nuclear submarine, INS Arihant, essentially a technology demonstrator, has been fitted with K-15 missiles with a range of 750 kilometers, which is woefully short of hitting anything significant in China, which is currently a prime adversary for India.
Even in a conflict with Pakistan, it would only have targets within the range of K-15, the first indigenously developed short-range submarine-launched ballistic missiles, in the southern region of the country.
This will not be the case with INS Arighat, which is equipped with a K-4 with a range of 3,500 kilometers.
In case of a nuclear conflict, the highest level of survivability lies with equipping nuclear-powered submarines with ballistic missiles with sufficient ranges. Since the submarine-launched ballistic missile first came into being, it has been considered the most survivable delivery system, as ocean depths remain opaque to a large extent.
One of India’s biggest challenges in the sea leg of nuclear deterrence is that an underwater vertical launch system is among the most sophisticated and complex weapons since it demands stability, speed, and accuracy in two mediums—water and atmosphere.
Hence the launch of the K-4 missile from INS Arighat is epochal for the Indian Navy.
As Manpreet Sethi, a nuclear expert at the Center for Air Power Studies, adds in her issue brief: “Unless the SLBMs have a range that can help deploy the submarine out of harm’s way, the vessel would not only be constrained for deployment but also become more a liability than an asset. India is yet to develop missiles with adequate ranges.”
The test-firing of K-4 from INS Arighat changes this. The need for long-range submarine-launched missiles corresponds to the increasing tensions in the Indo-Pacific region.
Only China has SSBNs in the Indian neighborhood. These have been deployed in the past for “counter-piracy patrols” off the east coast of Africa. However, Chinese anti-submarine warfare is in a nascent stage.
Given the threat assessment for India, SSBN promises a guarantee of survivability of nuclear retaliatory capability. With its long coastlines and peninsula, the SSBNs can remain hidden in ocean depths during the conflict to ensure the survival of second-strike capability.
India is expected to commission its third nuclear submarine, INS Aridhaman, in 2025.
The induction of INS Aridhaman will mean that India’s second-strike nuclear capability will be fully operationalized by next year. INS Aridhaman (Destroyer of Enemy) will also be equipped with K-4 submarine-launched missiles.
The Aridhaman will be followed by another advanced SSBN, the codenamed S-4, and another unnamed fifth SSBN to be armed with the 5,000-km range K-5 submarine-launched ballistic missile.
For nuclear deterrence, one submarine always needs to be on patrol. If Arihant is in and out of the harbor, it is not exactly a deterrent. At least 3-4 SSBNs are needed—one can keep on patrol when one may be in port, one goes for patrol, and one comes back.
No First Use
The test has come at a time when there has been debate about India forgoing its No First Use (NFU) policy as lines between conventional and nuclear deterrence are fast becoming blurred. The Indian NFU policy is based on three tenets— credible minimum deterrence, massive retaliation, and NFU.
But in the face of China amassing nuclear weapons, these have become irrelevant. The NFU limits the size of India’s arsenal, and the capability difference between New Delhi and Beijing is becoming starker with each passing year.
Communication Challenges With A Submarine Carrying Nuclear-Tipped Missile
India is fast moving towards fully operationalizing its nuclear deterrence; it has to work towards setting a system in place to ensure the nuclear submarine can carry out effective communication with the command.
The nuclear-powered ballistic submarines do not carry live missiles. The missile systems are demated through a system of controls and a string of permissive action links to ensure that unauthorized arming and launching of nuclear weapons without the proper codes from the command authority does not take place.
India’s strategic planners face the problem that SSBNs communicate via very low-frequency systems, which limit the types of messages they can receive. This raises the possibility that the submarine could miss a code from the command authority to arm a missile and carry out a strike.
