By Commodore Anil Jai Singh, IN (Retd)
The firing of the K4 ballistic missile from the Indian Navy’s recently commissioned ballistic missile nuclear submarine (SSBN) INS Arighat on November 28, 2024, marked a significant milestone in India’s strategic imperative of validating the sea vector of its nuclear triad. This was perhaps the most notable amongst various encouraging developments in India’s submarine warfare capability in the last few months. In October 2024, the Cabinet Committee on Security had approved the indigenous construction of two nuclear attack submarines, out of a possible six, that have been approved in principle earlier. On the conventional submarine front, the sixth and last of the P75 submarines is also ready for commissioning.
India became a nuclear weapon power in June 1998 after successfully carrying out five underground thermonuclear tests. Soon after that, the country placed a moratorium on further testing in line with its stance on nuclear non-proliferation. This was soon followed by a nuclear doctrine, the cornerstones of which were ‘No First Use’ (NFU) and ‘minimum credible deterrence’.
NFU meant that India had officially declared its position of not being the first to launch a nuclear strike, which naturally meant that the country would have to develop a retaliatory capability that would deter an adversary from launching a first strike on India due to the fear of a debilitating response.
Soon after these 1998 tests, India developed its land-based and air-launched nuclear weapon delivery platforms but the ability to do so from the sea was lacking. Thus, the country’s nuclear triad was incomplete.
In 2017, the commissioning of the indigenously built INS Arihant, India’s first ballistic missile nuclear submarine addressed this deficiency. In November 2018, INS Arihant successfully completed its first deterrence patrol. This was a significant milestone, and was given due recognition at the highest levels. The Prime Minister personally felicitated the crew and remarked that this patrol had ensured that the country would never be vulnerable to nuclear blackmail.
Modern submarines can be classified into three types. The first type includes the nuclear-powered and nuclear-armed ballistic missile submarines, also called ‘boomers’ and referred to more commonly as SSBNs. The second category comprises the nuclear-powered and conventionally armed platforms referred to as SSNs. These provide the cutting edge offensive war fighting capability to a navy. With their unlimited endurance, high speeds and lethal weaponry including long range precision guided land-attack cruise missiles, they are an integral part of blue water navy. The third type comprises diesel-electric submarines, also known more commonly as ‘conventional submarines’ and referred to as SSKs. These are more affordable and are ideally suited for operations in a defined theatre and in littoral and shallow waters. Their inherent limitations of speed and endurance and their vulnerability to detection due to their requirement of frequent battery charging is also now being addressed with modern technologies like air independent propulsion (AIP) and lithium-ion batteries (LiB)
Unlike SSNs and SSKs, SSBNs are not meant for conventional war fighting. They are strategic platforms and effectively define a country’s strategic posture. Their destructive capability has made them the ultimate deterrent against any nuclear misadventure by an adversary. Their inherent advantage of stealth, concealment, mobility, flexibility and agility make them a country’s most potent expression of power projection at strategic level and the preferred choice for effective deterrence; the presence of SSBNs with their lethal arsenal capable of destroying the world many times over was the main reason that the four-decade-long Cold War remained ‘cold’ despite numerous provocations from both sides and the world coming to the verge of a nuclear apocalypse on more than one occasion.
It is not a coincidence that, other than India, the only countries with SSBNs are the five permanent members of the Security Council. While three of these (the US, China and Russia) have large arsenals in keeping with their global superpower aspirations, the UK and France have also ensured that they have never compromised on this capability, notwithstanding their economic constraints and reduced defence budgets.
SSBN deployment is very different from deployment of other military systems. It involves a complex command, control and communication architecture. The decision to launch a nuclear weapon will be taken at the highest political level in the country. The order to do so at a specific time on a specified target with the accurate coordinates of its location, hundred or perhaps even thousands of miles inland, has to be conveyed to a submarine deployed hundreds of miles away from the shore and hundreds of metres below the surface of the sea. The enormity of this decision necessitates that the command and control structure has to be absolutely fool-proof, as there is absolutely no scope for making a mistake. On board the submarine, the commander and his crew have to be trained and ready in all respects to launch the weapon as ordered. The authentication of the orders and the command to launch, the pre-launch onboard protocols, the accuracy of the target parameters and the knowledge that this is a point of no return, and could ignite a nuclear conflagration, are all factors that will influence this decision at every level.
In India’s case, this could become even more complex. Its ‘No First Use’ policy means that it will not be the first to launch a nuclear strike. This means that there has to be enough redundancy built into this complex command, control and communication architecture and robustness to enable the delivery of retaliatory or second strike even when the country is itself under a nuclear attack.
For a country’s second strike capability to be an effective deterrent, at least one SSBN should be on patrol at any given time. To ensure ‘continuous-at-sea-deterrence (CASD) a minimum force level of at least four SSBNs is required as one or more could be under maintenance, one could be transiting to a patrol area or returning from one, while one would be on patrol. While the US, Russia and China are developing large nuclear arsenals to align with their global superpower ambitions, France and the UK have always maintained a force level of four SSBNs to ensure CASD. In 2024, the Royal Navy completed 55 years of CASD.
India presently has two SSBNs in commission – INS Arihant and INS Arighat – with the latter commissioned recently (on August 29, 2024). This has greatly enhanced the country’s nuclear deterrence capability, but what is most encouraging is that India is also developing a minimum force level of four SSBNs. Soon after the news of Arighat’s commissioning appeared in the media, photographs of the third SSBN currently being fitted out alongside appeared in the media. It is also understood that a fourth SSBN is under construction. These two submarines are expected to be larger than the first two, and capable of a larger and more lethal nuclear weapon complement. Hence, one could expect that within about five years from now, India would have a potent and credible capability of ensuring CASD. This will send a strong message to our adversarial nuclear neighbours, particularly Pakistan, which keeps parroting its nuclear rhetoric.
The commissioning of INS Arighat and the firing of a K4 missile from it highlighted two significant aspects. The first was that India has proved its military technology capability with the indigenous construction of two SSBNs and an Intermediate Range Ballistic Missile (IRBM). The second was the confidence amongst the decision-makers, the submarine builders and the submarine crew of their product, which was reflected in the maiden firing of the K4 missile from INS Arighat within three months of its commissioning.
The K4, with a range of 3,500 kmis a quantum leap in capability from the earlier Sagarika which was a good technology demonstrator with a range of about 750 km. Now that India has mastered the physics and chemistry of ballistic missiles with this successful firing, it is expected that New Delhi will soon develop missiles of greater range and lethality to complement its strategic posture and its SSBN capability built into this complex command, control and communication architecture. The other SSBN operating navies, including the Chinese (PLA) Navy, have an arsenal of ICBMs with ranges exceeding 8,000 km, which greatly enhance their ability to engage targets well inland, while deployed in safe bastions, thus minimising the risk of detection.
India is now one of only six nations with an undersea strategic deterrence capability. As the country progresses towards consolidating this capability with bigger and better SSBNs and longer range ballistic missiles, not only will it not be vulnerable to any nuclear or conventional coercion, but will also have a rightful claim to a position at the top table in the UN Security Council.
