Indian SSBN Arihant's Deterrence Shortcomings

The peculiar history of India’s long quest for a nuclear submarine leaves a long shadow over Arihant’s [Wiki link] capabilities.

India’s nuclear submarine program began in 1966 with feasibility studies on marine nuclear propulsion. Rather than being driven by any military necessity, the program was influenced by considerations of the nuclear establishment’s organizational prestige. As Homi Bhabha, father of India’s nuclear energy program, argued at the time, maritime reactors “could demonstrate India’s impressive capabilities in the field of nuclear energy.” Military justification for the program came much later when, during the 1971 Bangladesh war, the United States sent the aircraft carrier USS Enterprise into the Bay of Bengal to support Pakistan. Thereupon, as a conventional fighting platform, nuclear attack submarines attracted the attention of the Indian Navy because they could raise the threshold of superpower intervention in the region. However, the nuclear scientists could not produce a viable marine reactor. In the early 1980s, therefore, the Indian Navy turned to the Soviets for assistance.

In April 1982, the Soviet Union agreed to lease an attack nuclear submarine (SSN) to the Indian Navy and provide technical assistance to India in building its own submarines. This was the beginning of Project Samudra (Project Ocean), which was to include two vessels codenamed S-1 and S-2.

The stated intent was to produce a “cost-effective deterrent against Pakistan’s enlarging military machine,” according to a top-secret report explaining the program that I obtained from a former government official. The larger objective of these acquisitions, however, had little to do with nuclear deterrence — it was directed towards the growing naval presence of the great powers in the Indian Ocean, more focused on conventional operations than nuclear issues. The report stated, “more significantly, such acquisitions would enhance India’s credibility particularly in view of the increasing presence of the outside powers in the Indian Ocean.”

Project S-1 culminated with the loan of a Soviet Charlie-class SSN in 1988. Project S-2 paved the way for the establishment of the Advanced Technology Vessel (ATV) Directorate, a dedicated research and development agency responsible solely for building an indigenous SSN. The project suffered major delays as India’s nuclear establishment continued to face technological hurdles in producing a viable reactor design. Still, the path was set: India was designing and developing a nuclear attack submarine.

The Indian and Pakistani nuclear weapons tests of 1998 changed the nature of India’s nuclear submarine program. Indian decision-makers were keen to explore avenues that could render their nuclear forces more survivable, including placing nuclear weapons at sea. The first step towards building a sea-based deterrent was to place modified Prithvi missiles on board two Sukanya-class missile boats. The ATV Directorate, however, soon proposed modifying the nuclear attack submarine into a strategic weapon system. The navy was also keen to have its share of the nuclear pie. Thus, soon after the 1998 nuclear tests, India decided to convert what was originally designed as a nuclear attack submarine armed with cruise missiles for conventional naval operations into a strategic weapon system for nuclear delivery. Project S-2 became the first of India’s SSBNs.

Yet this revised mission left the program highly limited in its capabilities. India had started developing a 300-km earth-skimming cruise missile called Sagarika with Russian help in 1991. When India decided to convert the attack submarine into an SSBN, the size of the boat and its missile block was fixed based on the earlier SSN design — meaning only a modest missile with limited range could be retrofitted in. The only option was to replace the Sagarika cruise missiles with ballistic missiles that could carry a one-ton nuclear warhead. Today, the limited range of the K-15, the primary weapon system on Arihant, is the result of these post-hoc technological fixes. Arihant can carry 12 of these 750–1,000-kilometer range missiles, barely sufficient to hit a few major cities in retaliatory strikes against Pakistan, let alone Chinese targets. Its small reactor size also restricts its endurance at sea. In fact, the nuclear reactor onboard Arihant is of vintage Soviet design. Arihant is not Pakistan-specific by design but only by default: Its technological evolution rendered it incapable of anything else.

The burden of history continued to inform the trajectory of India’s SSBN program. To achieve meaningful deterrence vis-à-vis China, India not only needed more SSBNs, but also longer-range missiles that could strike deep inside Chinese territory. In the early 2000s, the Indian government, therefore, sanctioned the ATV Directorate to produce two more SSBNs of the S-1 type and to increase the range of the missiles to 3,500 kilometers. The increase in range entailed a consequent decrease in the number of missiles. The problem, again, was the fixed size of the submarine: Given the immutability of the S-1 design, the long-range missile could only be accommodated by increasing the missile diameter and reducing the total payload. But reduction in nuclear payload meant lesser bang for India’s buck, since it reduced the number of nuclear weapons it could deploy at any given time against China.

When the cabinet of ministers pointed out this problem in 2004, the ATV Directorate decided to include another missile block by increasing the length of the next two boats. Yet in 2006, a major technical review of the program concluded that all five boats proposed so far fell short of a true SSBN force capable of deploying intercontinental ballistic missiles (ICBMs) that could reach all parts of China. It also required a nuclear reactor double the size of previous boats that could endure longer operations at sea. The review committee recommended a new class of boomers with a reactor double the size of previous S-Class boats and capable of launching ballistic missiles in excess of 6,000 kilometers. S-5, as the boat is officially designated, was approved in 2015. This evolution of Project S is symptomatic of mission creep in India’s deterrent requirements, especially as it attempts to achieve deterrence parity with China. The piecemeal expansion of India’s nuclear submarine program severely undermines its deterrent capability. Until India fields an SSBN fleet with ICBM capabilities and improves upon the designs of its nuclear propulsion package, its sea-based deterrent will remain a paper tiger. As Admiral Arun Prakash estimates, it will take India “50-60 years” to field a credible SSBN force.

Arihant’s historical evolution also leaves doubts about its robustness and reliability. There are more than a few rumblings within Indian Navy circles regarding reactor designs based on second-generation Soviet submarines. Arihant’s first deterrent patrol lasted merely 20 days, suggesting endurance issues with its nuclear propulsion package. Finally, the Indian Navy would have to develop very robust infrastructure for training, maintenance, and repair of its SSBN fleet before the sea-based deterrent could be realized. In fact, the fleet has recently suffered from a series of accidents, including the 2017 mishap onboard Arihant. Only extensive operational experience will build the required confidence both in the men and the machine.

Given the twists and turns of its nuclear submarine program, the resulting technological limits, and the underlying problems with Soviet legacy platforms, Arihant’s first deterrent patrol is just a modest beginning in India’s effort to deploy a credible nuclear triad. For the prospective future, its nuclear deterrent will continue to rely on the land- and air-based legs. Indian decision-makers must accept the reality of this modest enterprise. Rather than engaging in premature triumphalism over Arihant, India should take a page from the Chinese playbook to hide its capacities and bide its time.

Even though Arihant, in its current form, has limited utility against China, its operationalization has nonetheless raised serious questions about how India would deploy its nuclear submarine force, whether this will entail a “ready-to-use” arsenal, and whether India has developed a sufficiently elaborate command and control mechanism to avoid unauthorized use of nuclear weapons. Such alarmist reactions, however, do not fully capture the efforts India’s Strategic Forces Command has made in establishing operational protocols for its SSBNs. The command’s standard operating procedures for the nuclear triad alleviate three major concerns. First, a sea-based deterrent would not engage in conventional operations, nor does it automatically translate into a “ready-to-use” arsenal. Second, custody of India’s nuclear weapons has not necessarily been delegated to the military. Last, India’s political leadership will maintain firm control over nuclear assets.

First, as far as deployment is concerned, India is most likely to follow a bastion strategy rather than putting its SSBNs on constant patrol in open seas. A “bastion” or a “citadel” model entails operating submarines in waters close to home and away from hostile forces. In India’s case, the most suitable geography is in the Bay of Bengal, the Andaman Sea, and in the Northern Indian Ocean. The Pakistani Navy has very limited capability to operate in these waters, while India’s overwhelming naval presence through its conventional fleet and anti-submarine warfare operations will be able to create a cordon sanitaire against Chinese submarine activity.

While some fear the nuclear submarines will have a dual (nuclear and conventional) role, my interviews with Indian Strategic Forces Command officials suggest otherwise. The nuclear submarines will remain solely under the operational command of the Strategic Forces Command, which handles nuclear forces, rather than the Navy, (which handles conventional naval forces). A clear division of labor between the two has been codified, reducing the risk that Indian nuclear forces at sea could get entangled in conventional operations.

In fact, Indian SSBNs would not operate alongside the Navy’s conventional fleet as any coordination could lead to the nuclear submarines’ exposure by enemy intercepts of fleet communications.

Relatedly, the operationalization of Arihant does not mean India’s nuclear weapons are now on hair-trigger alert. It is highly unlikely that the submarines will carry a nuclear payload during peacetime. In fact, insofar as India’s SSBN force will not perform constant patrols armed with nuclear weapons at all times, it does not entirely fit the definition of a true triad. India’s operational plans for its nuclear submarines consist of a three-stage process. The first is nuclear alerting, or mechanically mating missile launch tubes with missile canisters armed with nuclear weapons at specialized naval facilities. This would start at the first indications of a crisis situation (Strategic Forces Command defines a crisis not as the start of actual conflict, but any scenario where Indian decision-makers foresee a possibility of military escalation with Pakistan or China). The second stage involves dispersing the submarines on deterrence patrol. It is only after the boats receive political authorization that they will maneuver to predetermined positions to prepare for the eventual launch of nuclear weapons. This strategy does entail a risk of a “bolt from the blue” nuclear strike against India’s major naval bases, but decision-makers are willing to run this risk given the other legs of the nuclear triad and the inherent uncertainty that any first strike would eliminate all its nuclear assets. Since at least 2008, Strategic Forces Command has consistently strived to develop and put into practice such operational plans for India’s SSBN force.

Lastly, India has developed an elaborate command and control apparatus to maintain firm political control over its sea-based nuclear assets. When the submarines encounter a crisis situation, nuclear weapons will be physically mated with ballistic missiles, per the first of the three steps described above. For this reason, India needed positive command-and-control mechanisms to ensure that when authorized a launch will always occur and that unauthorized or accidental launches never occur. Former Strategic Forces Command personnel have told me in interviews that India has developed such mechanisms: Even after nuclear weapons have been mated with missile tubes, the military will not be in command of nuclear weapons. Any ballistic missile launch requires a two-step authorization, in which civilian authority plays a key role. Even in situations where an imminent enemy strike may be about to take out the submarine’s ballistic missiles, civilian authority will remain the sole custodian of India’s sea-based nuclear forces.

These operational procedures would require extensive testing and training, and a robust communications network. Strategic Forces Command has to establish beyond doubt that the controls will work under the fog of war and that decisions will be securely communicated to the submarines’ battle stations. The infrastructure for these communications has grown alongside the SSBN program, but will still take a lot of time to mature and attain operational effectiveness and reliability. These concerns will continue to cloud the readiness of India’s SSBN force.

Thus, Arihant’s operationalization should not lead to a conclusion that its nuclear weapons are now fully mated with delivery systems and that control has shifted to the military, as many alarmists seem to fear. India has strived to ensure complete political control of its nuclear assets at sea, ruling out any unauthorized use.

Indeed, Arihant’s problem is not that it has nuclear weapons on hair-trigger alert, that it suffers from loose command and control, or that it increases the risks of accidental nuclear use. Rather, Arihant is yet another manifestation of India’s deterrent dilemma between China and Pakistan. As Pakistan responds to India’s sea-based deterrent, it will exacerbate the subcontinent’s nuclear tensions while providing no meaningful change in India’s nuclear deterrent vis-à-vis Beijing in the foreseeable future..."