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Nader Elheftiawy is a writer on defense issues who has published in numerous military and policy journals, including Astropolitics, Parameters and International Security. He is also a frequent contributor to the Submarine Review.

In a story recently broken by Jane’s Defense Weekly, it was reported that North Korea may be developing submarine-launched ballistic missiles (in this case knock-offs of the R-27/SS-N-6)1. While it may seem astonishing that backward and bankrupt North Korea is pursuing something as ambitious as a fleet of ballistic missile subs, such a move fits a broader pattern. Smaller and newer nuclear powers in general are looking into submarines as platforms for such weapons, including not only North Korea, but also India, Israel and potentially even Pakistan.

This is in part a prestige issue, enhanced prestige being one of the principal benefits of nuclear weapons-and the prestige of a state which arms its submarines with them is higher still.3 Bureaucratic politics is also a factor, the nuclear mission being a good way for navies to angle for a bigger slice of the budget. There is, however, also a practical element involved in the diversity and flexibility offered by a triad of land-sea-and air-based weapons, each element of which has its advantages. Accuracy and quick reaction-time are traditionally the edge that land-based ICBMs can bring to bear. Aircraft, as with strategic bombers, are highly flexible and recallable.

Submarines, however, are stealthy and survivable, given the sheer difficulty of hunting them down, and it is the latter attribute which may be of the greatest interest to insecure states seeking to maximize the survivability of a small nuclear arsenal. Submarines, admittedly, are not the only option in this area. Mobile launchers and under-ground bunkers and tunnels certainly confer a measure of protection, and may be more feasible. It is also possible to base missiles on Surface ships, either warships or launch vessels disguised as merchant shipping, an option that the North Koreans are also thought to be pursuing as the Soviets did before them in the Project 909 and 111 vessels of the early 1960s.

Nevertheless, the increasing effectiveness of air-and space-based surveillance, a shortening sensor-to-shooter cycle, and the stealth, defense-suppression and precision-strike capabilities of the most advanced air forces hold out the possibility of at least partial effectiveness against a dispersed, concealed missile force. (Indeed, the B-2 bomber was expressly designed for the purpose of ranging about Soviet airspace with impunity to hunt down mobile ICBMs.) Even on a theoretical level air and space power simply can not be as effective against submarines. 4 Two options exist in this area, ballistic missiles and cruise missiles, and this article will discuss the situation with regard to each in turn.

Third World SLBMs

The history of the submarine-launched ballistic missile goes back to World War II, when the German navy hit on the concept of using its U-boats to tow encapsulated V-2s -weapons which would have been developed against the United States in 1946, had the war dragged on. While both submarines and ballistic missiles have proliferated widely, the latter have tended to remain land-based, only the five permanent members of the United Nations Security Council (and also the five original members of the nuclear club) actually possess ballistic missile submarines-and China’s status in this area has generally been questionable, given its difficulties with its Xia submarine program.

This, however, is beginning to change. Besides North Korea, India has displayed an interest in ballistic missile submarines of its own. Such a program could well be an overambitious boondoggle, another instance of Pyongyang1s overreaching in the course of a prestige project, as with its space program. (This may also have been the case with China’s Xia program, and could well be the case in the near-term with India’s plans for its own missile boats, given its own unhappy experiences with indigenously-built subs.)

This is due in part to the slowness with which the nuclear weapons that are their primary weapon have spread, but also to the formidable technical problems involved in a submarine-launched ballistic missile program.5 First and foremost among these is the problem of acquiring adequate submarines. Today’s diesel boats are not meant to cross oceans as those of World War Il were, but rather to operate in coastal waters, and the equivalents of towed V-2s in capsules may be judged not worth the trouble. For the most part it is the nuclear submarine (again, a monopoly of the UN Security Council’s permanent members) that makes the sea-launched nuclear missile practical, given the sheer capacity necessary to contain a significant number of missiles, their ability to remain submerged for extended periods and deploy at strategic distances -and their need to be able to avoid or survive attacks by other, nuclear-powered attack boats.

There are also the design problems inherent in the missiles themselves, since this is not a matter of taking an ordinary ballistic missile out of its silo on land and dropping it into a submarine’s launch tube, if only because they are too large. Given the need for miniaturization and reduced certainty about firing positions, submarine-launched ballistic missiles are typically shorter-ranged and less accurate than their land-based cousins at a given level of technical sophistication and expense. Only the Trident II has a comparable combination of throw-weight, accuracy and range to land-based missiles like the Minuteman Ill, making it the first SLBM to have a “credible hard target kill” or “first strike” capability.6 There is little question that North Korea’s effort to develop its own submarine-launched version from the Soviet SS-N-6 has met with far greater difficulty than the development of the land-based variant, which is also believed to have greater range-possibly 4000 kilometers to the sea-launched missile’s 2500.

Finally, maintaining the deterrent at the level of at least one operational submarine deployed at all times can be relatively taxing. China’s Xia program does not suffice in this regard, even after three decades. Britain and France have generally required four or more for this purpose. In navies using poorer equipment or having lower proficiency, more vessels may well be required, and as a practical matter few of them can operate a large enough Submarine Force to commit the requisite percentage of it to this mission-though some could try and do it on the cheap. There is no reason why (geography permitting) a submarine can not fire its missiles from in port, or why they can not attempt to conceal the facts in a situation where they have no operational submarines.

Nevertheless, these problems are not necessarily insurmountable. There have been diesel ballistic submarines, notably the Soviet Golf-class boats which were built in the 1950s and continued to serve in the Soviet navy until 1990. China also worked with Golf-class submarines for some decades, and North Korea’s own program is believed to be based on a purchase of used Soviet Project 629A (Golf) and Project 641 (Foxtrot) submarines (the Foxtrot of course being the basis for the Golf).7 In contrast with larger, more modem vessels these had their deficiencies, being not only slower and having less endurance, but able to carry only relatively short-ranged missiles and needing to surface for twelve minutes to fire them. Even so, for the purposes of a small state deterring an opponent, rather than planning on the waging of a superpower-level strategic nuclear war, not every ballistic missile submarine must carry twenty-four missiles with ten warheads a piece to provide a credible strategic deterrent. The submarine’s inherent stealth, and the challenges inherent in shooting down ballistic missiles, make virtually any workable capability a factor.

Technological and political changes could also improve the performance of such systems. Improvements in conventional propulsion (like air-independent propulsion) make the most recent diesel boats more formidable opponents. Given the regionalization of most future conflicts, and the longer reach of missiles, they need not be able to deploy to strategic distances to get the job done. Moreover, North Korea’s exceptionally large submarine fleet-twenty-six diesel patrol boats, excluding the dozen Foxtrots and Golfs purchased in 1993-makes it an exception to the rule. The same would apply to India, which operates nineteen submarines, five of which might perform the missile*carrying role according to reports in the press over the years.

Other, smaller submarine forces are unlikely to do the same. Iran, with its Submarine Force limited to three Russian Kilos (which seem to have been purchased for interdiction in the Strait of Hormuz), is unlikely to follow suit even if it were to acquire nuclear weapons. While Pakistan would likely feel pressured to develop capabilities matching India’s at some point, it too would be hard-pressed to dedicate a portion of its seven-boat Submarine Force (excluding small, special-forces versions) to the ballistic missile mission. The Israeli navy, which has three German-built Dolphins, is eschewing the ballistic missile option-in favor of cruise missiles.

Cruise Missiles: The Israeli Choice

The ability to fire anti-ship cruise missiles is increasingly a standard on attack boats, both nuclear and diesel, and a range of land-attack cruise missiles which can be fired from a submarine has long existed (as with the American Tomahawk or Russian SS-N-21 ). Pakistan’s French-built Agosta and Daphne-class submarines can fire Harpoon and Exocet anti-ship missiles, and Israel’s Dolphins can also fire the Sub-Harpoon. Some of India’s Kilos are configured to fire anti-ship missiles, and the same goes for China’s Song (diesel) and Type 93 (nuclear) submarines. Some of the latter may also be equipped with land-attack missiles, a capability that Britain imported in the Tomahawk and repeatedly demonstrated in Kosovo, Afghanistan and Iraq. In the foreseeable future a number of Indian submarines may also be configured to launch land-attack missiles.

Israel, however, has arguably taken the lead in developing a sea-based nuclear deterrent around sub-launched cruise missiles.9 While Israel possesses ballistic missile technology, andat least the capacity to build weapons with intercontinental reach, it is instead, developing a cruise missile capability, likely based on the indigenous Popeye Turbo missile.

Such an approach has much to recommend it from the standpoint of a small navy with limited resources. Medium-and long-range cruise missiles are slower, shorter-ranged and more susceptible to air defenses but, aside from being more easily built on a limited budget, they are considerably Jess demanding in terms of payload. As a consequence they do not require specialized vessels, being insertable into the diesel submarines that are easiest to come by, and which can be committed to other missions. They can also be more accurate. The latest versions of the Tomahawk may be accurate to within a meter because of satellite navigation aids, thus being within the Circular Error Probability of the most accurate ballistic missile.

Other states are likely to follow course. Especially if they encounter difficulty with ballistic missile programs, China and India will see fit to proceed with the nuclearization of their sub-launched cruise missiles. Given their smaller fleets, forces like Iran’s and Pakistan’s may also pursue this option, as could any other states which in the future seek to acquire weapons of mass destruction, not only nuclear, but also biological or chemical. (While rarely dis-cussed as proliferators the same could be the case with South Korea or Taiwan, for instance, should they opt to nuclearize.) Indeed, equipping subs in this way may be one of the ways in which poorer or smaller states can maximize the potency of their Submarine Forces.

Conclusions and Recommendations

Especially after the recent revelations about North Korea, it is important to recognize that just as with combat aircraft capable of delivering nuclear weapons (such as the F-l 6s Pakistan purchased from the U.S.), submarine proliferation is of concern to those following the spread of weapons of mass destruction. Nevertheless, North Korea’s particular approach is unlikely to be representative of such efforts, as Israel’s decision to go with cruise missiles demonstrates. For logistical and political reasons it is a far simpler matter to keep large, nuclear-powered subs and ballistic missile technology from spreading than it is to keep diesel boats and cruise missiles from proliferating, but the effort must be made. Political counter proliferation efforts aside, threat planning in the future may do well to include cruise-and ballistic-missile armed submarines in the arsenals of rogue states in the future. This may have implications for homeland security planning, but also represent an important mission for American and allied submarine forces in regional conflicts

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