*This article will soon appear at the Global Intelligence Trust

Sam Seitz

Submarines play an integral role in nuclear deterrence. Their stealth and ability to loiter near rival countries’ shorelines make them an ideal platform for launching nuclear strikes and guaranteeing second strike capabilities. Since their introduction, submarines capable of launching nuclear ballistic missiles, or SSBNs, have been the exclusive domain of the five recognized nuclear powers: The United States, Russia, China, France, and the United Kingdom. However, this is no longer the case. Israel has possessed a sea-based deterrent for some time, and India and Pakistan are both investing heavily in SSBN capabilities (1). Even North Korea has begun conducting tests of submarine-launched ballistic missiles, though they have had only limited success (2). As the newer nuclear powers continue to acquire and perfect their undersea deterrents, the older nuclear states like China and the United States are working to upgrade their fleet of SSBNs. With the recent unveiling of the Chinese Jin-class and the American development of the Ohio Replacement Submarine, the next generation of nuclear subs appears to be just around the corner (3). If paired with effective command and control networks and trust building measures, the development of secure arsenals capable of withstanding a nuclear first strike could create greater stability. However, noisy submarines engaging in risky and provocative actions might also generate mistrust and increase the risk of a nuclear accident. Therefore, understanding this rapidly changing environment is crucial for policymakers and non-proliferation advocates alike.

SSBNs were initially developed in an effort to provide greater security for the nuclear arsenal. In the early days of the Cold War, both the United States and Soviet Union had relatively small arsenals that were designed to be delivered either by bombers or ICBMs. However, these two delivery methods – bombers and ICBMs – were highly vulnerable to a nuclear first strike, as they were easy to locate and destroy. With accurate intelligence, either one of the superpowers could have launched a nuclear first strike on their opponent’s silos and bombed their runways, all but eliminating their ability to retaliate. This problem was partially mitigated by a number of innovative strategies like the development of road-mobile ICBMs capable of driving to different locations and the adoption of an airborne alert posture. However, these methods were imperfect and not guaranteed to safeguard a country’s retaliatory capabilities (4). Thus, submarines capable of launching ballistic nuclear missiles were developed to create a more survivable delivery mechanism. Of course, submarines are still vulnerable to preemptive attacks: they can be tracked and sunk by adversaries. However, their ability to remain submerged for extended periods of time in vast oceans makes it nearly impossible for one country to entirely eliminate the sea-based nuclear deterrent of its adversary. Furthermore, as Andrew C. Winner and Ryan W. French posit, submarines are advantageous because “depending on where a submarine is deployed, it may increase surprise, provide shorter flight times, or enable an attacker to strike from a direction that reduces the effectiveness of ballistic or cruise missile defenses (5).” In short, submarines represent a highly survivable and reliable nuclear delivery system.

SSBNs do have some significant drawbacks, though. The most significant is the complicated command and control network that must be developed in order to effectively operate a sea-based deterrent. The difficulty emerges from submarines’ relative autonomy: With submarines designed to stay submerged and silent for significant periods of time, it can be difficult for civilian leaders to effectively communicate with submarine commanders (6). This can lead to dangerous situations in which submarine commanders are not on the same page as their civilian leaders. For example, during the Cuban Missile Crisis, the Soviet submarine B-59 almost fired a nuclear-tipped torpedo at an American warship (7). Submarines can also be detrimental to crisis stability if they are easily detected. Early submarine designs are usually noisy and lack the requisite stealth materials to serve as an effective second strike-capable platform. When these platforms are deployed, they can often lead to suspicion and mistrust if they approach the waters of an adversary. Moreover, their loud acoustic signature means they are more likely to be detected and tracked, making a dangerous incident at sea far more likely.

The three countries that have most recently entered the SSBN race are India, Pakistan, and North Korea. Of these three, India is the most advanced. With the Arihant having already completed its sea trials, India now has its first SSBN, and there are currently plans for India to construct four more Arihant-class ships. Indeed, Aridhaman, the second ship of the class, is already being built (8). India’s Arihant-class ships will be capable of launching 12 K-15 Sagarika SLBMS with a range of 450-1,200 miles or four K-4 SLBMs with a range of 2,200 miles, significantly augmenting India’s nuclear strike capabilities (9). Despite the Arihant’s impressive capabilities, it still suffers from a number of issues frequently found in first generation subs. In particular, it has a noisy acoustic signature, which renders it easy to track and monitor. This, in turn, reduces the deterrent value of the Arihant, because the stealth and ambiguity inherent in SSBN operations will be seriously undermined. Furthermore, the relatively short range of India’s SLBMs mean that the Arihant-class will be forced to move dangerously close to adversaries’ shores, potentially triggering a crisis (10). Nevertheless, it is clear that India has made great strides in improving and modernizing its sea-based deterrent, and India’s SSBN force will likely improve precipitously over the next decades.

Unsurprisingly, Pakistan is also seeking SSBNs in an effort to match Indian nuclear modernization. With tensions constantly simmering between these two South Asian neighbors, it is likely that a submarine arms race might erupt, with each side trying to acquire more potent and secure delivery mechanisms than the other. Pakistan currently lags significantly behind India in the development of submarines capable of launching nuclear ballistic missiles. However, it has made important first steps toward the development of an SSBN force. Pakistan has already developed a missile – the Hatf-IX/Nasr – compact enough for use within the confines of a submarine missile bay. Pakistan also began developing the command and control infrastructure necessary for directing and monitoring a sea-based nuclear force when it unveiled the headquarters of the Naval Strategic Forces Command in 2012 (11). At this point, it is still unclear which submarine platform will be utilized for Pakistan’s SSBN force, but there is speculation that Pakistan might choose either the Agosta 90B diesel electric submarine or the Chinese built Yuan-class, of which Pakistan ostensibly possesses eight (12).

There is also evidence to suggest that North Korea is seeking to develop an indigenous SSBN force, although it still has significant barriers to overcome. The most pressing obstacle for North Korea is the development of a reliable missile system capable of being launched from a submerged submarine. Recently, North Korea has tested a number of SLBM systems from submerged barges (13). The majority of these tests have failed. Nevertheless, a number of analysts who specialize in SSBN systems estimate that North Korea could obtain a reliable SLBM system within around five years, the time it has taken other developed countries to perfect their sub-launched missile systems (14). Developing an effective and reliable missile system is not the only obstacle North Korea faces, however. It also needs to develop a submarine class stealthy enough to effectively guarantee North Korean second strike capabilities. While North Korea does possess an immense submarine force, its vessels are decrepit and antiquated, making it unlikely that they could serve the role of SSBN. North Korea’s military industrial base and manufacturing sector are also lacking and underfunded, making North Korea’s ability to develop an effective SSBN class suspect. The next few years will grant better insights into the direction of North Korea’s SSBN program and provide more clarity regarding North Korea’s technical capacity to design and develop the necessary systems.

The development of these nuclear capable submarine forces is alarming for a number of reasons. First, the relative novelty of SSBN forces in East and South Asia means that there are no clearly established rules of the road. It is possible and even likely that an incident at sea involving new SSBN forces might generate a diplomatic crisis and risky military posturing. This danger is compounded by the fact that no Asian nuclear power, including China, has a well-developed submarine command and control infrastructure in place, meaning that high-ranking civilian and military leadership may not have complete control over SSBN forces out on patrol (15). This precarious dynamic is only further exacerbated by the relatively small and technologically deficient SSBN forces that these powers will possess. The short range of SLBMs guarantees that submarines will be forced to sail close to adversaries’ waters to hold them at risk. This, along with the poor acoustic signatures of early model SSBNs, increases the chances of detection, making a risky encounter at sea more likely. The relatively small SSBN fleet size of nuclear powers like China, India, and Pakistan is also perilous in that it makes the deployment of any one SSBN more significant. While countries like the United States maintain continuous SSBN deployments to maintain effective deterrence, countries with smaller SSBN forces may lack the requisite number of ships to maintain continuous deployments. Thus, when they do deploy a SSBN, it will be viewed as a far more significant move, as it is not part of a routine operation, but instead marks a meaningful change in nuclear posture. While the development and deployment of SSBN forces might be a stabilizing force in the long run, providing secure second strike capabilities and alleviating policymakers’ fears of nuclear decapitation strikes, these actions risk exacerbating tensions in the short term.

There is little that can be done to halt this developing SSBN arms race. However, there are clear steps that can and should be taken to mitigate the risks inherent in nascent SSBN forces. First, countries should engage in confidence-building measures such as regular summitry between political leaders and naval officer exchanges. Of course, there are inherent limits regarding the degree of transparency an SSBN force can have: One of the most significant advantages of SSBNs, after all, is their secrecy and stealth. Nevertheless, frequent communication and trust-building between high-level civilian and military government agents will go far to minimize distrust and foster greater cooperation. Another suggestion worth considering is one proposed by Brendan Thomas-Noone and Rory Medcalf in their Lowy Institute Report: exchanges with established nuclear powers (16). As Thomas-Noone and Medcalf point out, both the U.K. and France have decades of experience operating SSBNs, and they both have SSBN forces of similar size to those of China and India. Thus, they would be able to give valuable insights and share best practices with the inchoate forces of Asia. This would go a long way in creating more professional and effective command and control networks and SSBN forces in the Indian and Pacific Oceans.

Despite the end of the Cold War, questions of deterrence theory and nuclear posture remain highly relevant. Indeed, despite the smaller arsenal sizes of states like North Korea, India, and Pakistan, the nuclear forces of these incipient nuclear powers might actually be more dangerous because of their lack of experience. Unlike the Cold War, marked by a well-developed understanding between the two superpowers, this new nuclear age is characterized by nuclear powers who lack the experience and capabilities to ensure the effective execution of a deterrence strategy (17). Thus, it is imperative that mature nuclear powers work to guide these relative newcomers, and that these young nuclear powers work among themselves to develop de-escalation hotlines and codes of conduct in order to ensure that crises never escalate to the nuclear level.

Works Cited

(1)- For a comprehensive history of the Israeli, Indian, and Pakistani nuclear programs, see Narang, Vipin. Nuclear Strategy In The Modern Era. Princeton: Princeton University Press, 2014. Print.

(2)- Lewis, Jeffrey. “DPRK SLBM Test.” Arms Control Wonk. May 13, 2015. Web.

(3)- For an analysis of Chinese SSBN modernization, see “Does China have an effective sea-based deterrent?” CSIS China Power. 2016. Web. For analysis of the Ohio Replacement, see Majumdar, Dave. “Beyond the Ohio-Class: Inside America’s Next-Generation Missile Submarine.” The National Interest. May 19, 2016. Web.

(4)- For the dangers inherent in airborne alert, see Krepon, Michael. “Ghosts in the Machine.” Arms Control Wonk. September 30, 2013. Web.

(5)- Winner, Andrew C. & Ryan W. French. “Rip currents: The dangers of nuclear-armed submarine proliferation.” Bulletin of the Atomic Scientists, 72(4) (2016): 223.

(6)- Carter, Ashton B., John D. Steinbruner, and Charles A. Zraket, eds. Managing Nuclear Operations. Washington, D.C.: The Brookings Institution, 1987.

(7)- Burr, William and Thomas S. Blanton. “The Submarines of October: U.S. and Soviet Naval Encounters During the Cuban Missile Crisis.” George Washington University National Security Archive. October  31, 2002. Web.

(8)- Winner, Andrew C. & Ryan W. French. “Rip currents: The dangers of nuclear-armed submarine proliferation.” Bulletin of the Atomic Scientists, 72(4) (2016): 224.

(9)- LaGrone, Sam. “India’s First Boomer Leaves On Acceptance Trials.” USNI. April 20, 2016. Web.

(10)- Thomas-Noone, Brendan & Rory Medcalf. “Nuclear-armed submarines in Indo-Pacific Asia: Stabiliser or menace?” Lowy Institute. September 2015. Web. pp. 7-8.

(11)- Winner, Andrew C. & Ryan W. French. “Rip currents: The dangers of nuclear-armed submarine proliferation.” Bulletin of the Atomic Scientists, 72(4) (2016): 225.

(12)- Ansari, Usman. “Pakistan, China Finalize 8-Sub Construction Plan.” Defense News. October 11, 2015. Web.

(13)- IHS Jane’s. 2016. “North Korea’s Unconfirmed Fourth Test of Submarine-Launched Ballistic Missile Underscores Its Increasing Capabilities, Including Nuclear Weapons.” Jane’s Country Risk Daily Report, April 8.

(14)- Hardy, J. 2015. “Analysis: North Korean SLBM Test Leaves More Questions than Answers.” Jane’s Defence Weekly, May 12.

(15)- Thomas-Noone, Brendan & Rory Medcalf. “Nuclear-armed submarines in Indo-Pacific Asia: Stabiliser or menace?” Lowy Institute. September 2015. Web. pp. 10-11.

(16)- Thomas-Noone, Brendan & Rory Medcalf. “Nuclear-armed submarines in Indo-Pacific Asia: Stabiliser or menace?” Lowy Institute. September 2015. Web. pp. 16.

(17)- Yoshihara, T. & Holmes, J. R. Strategy in the Second Nuclear Age: Power, Ambition, and the Ultimate Weapon. Washington: Georgetown University Press, 2012. Project MUSE. Web. 29 Jul. 2016.