Russian Navy

Issues of SLCM control

Russia and the US pushed preparatory work to define start point in strategic nuclear weapons (SNW)

This Russian cruise missile is designed for destruction of ground targets. Photo from the book "Russian submarine forces"

In the course of the meeting between Russian vice-premier Sergei Ivanov and US vice president Joseph Biden held in Munich during 45th International Security Summit in July, high-ranking officials agreed to start negotiations on reduction of strategic nuclear weapons. However, starting point for disarmament policy were talks between Dmitry Medvedev and Barack Obama in April 2009 at G20 Summit in London. Essentially, from that very moment Russia and the US launched preparatory work to define positions of the parties in strategic nuclear weapons issue.


Rather scant information in media about course of the talks draws quite various and sometimes directly contrary appraisals of diplomatic and military officials. Anyway, most of disputants concur that those talks enlightened standpoints of Moscow and Washington on rather complicated and urgent problem of nuclear disarmament; provoke its discussion by experts. Complexity of that issue is redoubled by first-ever appeared interrelation between strategic offensive and defensive weapons.

We recall that in previous agreements they discussed and recorded defensive (ABM Treaty 1972) and offensive treaties (START-1 and SRSM) separately.

Since that time situation in the area of strategic stability abruptly changed as a result of unilateral activity of the US, and correlation between those two components has come to the fore; virtually, defensive and offensive elements are antipodes and that significantly complexifies on-going negotiations. Patient and mutually acceptable approach of both parties is essential to resolve extremely clouded issues, especially taking into account the US intentions to establish third missile defense area in Europe. Though recently there were statements that it could be deployed at Balkans, Turkey or Israel; that Russia could possibly take part in future European MD zone. Certainly, that would create more favorable conditions to reach mutually acceptable agreements between Russia and the USA.

Looking back, one should remember that during long-term negotiations on reduction of strategic nuclear weapons (under START-1 treaty) Moscow repeatedly raised a problem of necessity to control long range sea-launched cruise missiles – SLCM. Basically, difficulties in achievement mutually acceptable decisions in this matter were caused by considerable unbalance between Russian and American SLCM programs. Having long odds in cruise missile arsenals, the US party had been displaying obvious intent to keep them in future. Cruise missiles are massively deployed at US ships (according to some sources, dozens of ships).

During notably strained START-1 negotiations Moscow could not win consent of American side to liquidate SLCMs; they only decided to limit amount of operational nuclear SLCMs to 880. However, that was just a half-measure and did not provide efficient control over those arms. During meeting between Russian and American presidents held in Helsinki in March 1997, on insistence of the Russian Federation two leaders reached accord in necessity of reducing and control over SLCM at forthcoming talks on START-3.

Such close attention to SLCM problem is anything but casual. It is governed by basic performance characteristics and vast capabilities of sea-launched cruise missiles in different combat tasks. They are charge yield, target accuracy and flying range. Warhead yield of nuclear-tipped CM Tomahawk varies from 5 to 200 kiloton. By estimates of experts, Tomahawk and air-launched cruise missile ALCM-Â have design flying range up to 3,000 km. Russian cruise missiles SS-N-21 Granat have about the same range. This range is known as "operational", considering probability of maneuvering at target area and en-route maneuvers due to terrain relief, especially at low altitude flights. Practically, maximum range may be longer depending on complexity of trajectory.

Assumptions made by Russian experts show that American SLCMs deployed at nuclear-powered submarines might be capable to strike against almost all Russian ICBM silo launchers. That is theoretically possible in case of subs secretly come at launch positions in Barents Sea, Kara Sea, Sea of Okhotsk and Sea of Japan.

In the abstract, one should consider surprise attack of Russian cruise missiles in case of military conflict between the two countries. Their deployment at nuclear-powered subs near American coast could pose a convincing threat to the US.

Applying in SLCMs inertial guidance system in combination with landmarks and terrain relief tracking system needs preliminary flight route reconnaissance and provides uppermost guidance accuracy among strategic nuclear weapons, practically independent of flight distance. During first Gulf War circular error probable of CM impact point was about 60–80 meters. Such precision and reliability guaranteed high performance in mission – US ships launched 288 cruise missiles against Iraqi territory, 282 of them destroyed planned targets. On the other hand, new combat tasks place exclusive demands on target accuracy; that is an objective of leading military industrial companies.

Further increase in conventional SLCM accuracy should provide their use against hard pinpoint targets including command posts, communication centers, air defense facilities and ICBMs in hardened silos. In this case, to disable missile it is necessary to pierce armored silo cover by kinetic or cumulative effect of heavy charge. That needs a direct hit of silo cover. Achievement of such high precision will need SLCM flight correction at terminal phase by space-based facilities.


Serious problem in fighting with attacking SLCMs is low efficiency of launch warning systems. As it known, existing missile warning systems and bomber attack warning systems provide quite high reliability and effectiveness of timely detection. Appearance of cruise missiles in the US and Russian arsenals poses a rather complicated scientific and technical problem of early warning (EW) for both countries.

This situation is worsened by the fact that cruise missiles have insignificant radar cross section (RCS), about 0.1 square meters what is 10–20 times less than aircraft's RCS. Furthermore, CMs are quite weak sources of heat and sound what makes them difficult for detection. Another hampering factor for CM detection is absence of attributes distinguishing cruise missiles from civil aircrafts. Moreover, it is not practical to define which warhead is carried by a cruising missile – conventional or nuclear. Such low-observable parameters combined with high precision of SLCMs create real possibility to use them as first-strike weapon, especially against critical targets in enemy defense system. Nuclear attack by cruise missiles may be conducted just prior to full-scale strike of ground-based (ICBM) and sea-based (SLBM) ballistic missiles. In this case main targets for SLCM attack could be high-priority assets of governmental and military administration, communication centers, strategic aviation air bases, EW radars. Greatest problem for EW systems constitute submarine-launched cruise missiles as they can be secretly launched from indeterminate region of the World ocean and approach target from any direction.

Surprise attack of 50–60 nuclear SLCMs is capable to destroy all enemy bombers at air bases, ballistic missile subs at basing sites and disrupt command and control system; that may break up counterattack of strategic nuclear forces, especially ICBM. To accomplish that mission, 3–4 submarines would be enough. The most effective attack of SLCM would be in conditions of absence of strategic warning. Special expectation is laid on SLCMs when use against mobile ground-based missile systems (MGMS). However, to complete this task, it is necessary to improve missile control system giving CM the capability of in-flight retargeting by space-based surveillance and reporting system.

US SLCM Tomahawk, submerged launch. Photo by "Encyclopedia of ships" website


Unilateral agreed decisions to remove nuclear SLCMs from ships and subs were made by George Bush Snr. and Mikhail Gorbachev in autumn 1991 and later on confirmed by Boris Yeltsin. Those agreements were essential step towards averting danger of sudden SLCM attack; although it was just partial problem solution of SLCM threat reduce. Conventional cruise missiles are still at ships. Considering their features, main tasks of control should be determination of total amount of produced and deployed cruise missiles; possibility of reliable identification nuclear and conventional warheads; location of SLCM secret production and storage sites. That is explained by the fact they do not need any special launchers, can be launched from common torpedo tubes, have comparatively small size, are easy to transport and store. It is known that the US has three variants of SLCM Tomahawk: nuclear, conventional and anti-ship (conventional). Account must be taken of possible secret refitting of conventional CMs into nuclear ones; reconfiguration of ALCMs into SLCMs or short-range CMs into long-range ones.

Definition of counting rules for deployed US cruise missiles are much more complicated then those for Russian CMs; the reason is variety of CM launchers and huge amount of conventional cruise missiles so nuclear ones could easily "get lost" among them. In addition to torpedo tubes, the US have designed three more types of SLCM launchers: ÀÂL armored launcher, VLS surface ship vertical launch system and CLS capsule launch system deployed at Los-Angeles class subs. In the context of lifetime expiry of SLBM Trident-1 in 2005, US Navy leaders decided to retrofit four subs of that class into cruise missile carriers. In the USSR most of attack submarines were armed with 20-40 SLCM Granat (SS-N-21), and Project 949À nuclear-powered submarines have 24 SLCM Granit (SS-N-19) each. Those missiles may be launched from any standard 533-mm torpedo tube.

Considering features of cruise missiles, the control over them should include main focal lifecycle points of this kind of arms. Direct control over objects of production, maintenance and storage of SLCMs will create real possibility to control their number as well. Inspection of CM launchers on ships and subs could define quantitative limits for deployed SLCMs. The problem of secret replacement conventional warheads for nuclear ones exists. This reequipment may be performed in stationary conditions. Though this problem could be much simplified; it is known that Livermore National Laboratory has been working on that, developing changeable warheads for number of combat systems. That means necessity of ban on using changeable warheads on SLCMs. One should also consider strong resemblance of air-launched cruise missiles (ALCM) with SLCM. This implies that ALCMs may be launched by SLCM launcher with insignificant modifications. To prevent such threat, it is necessary to achieve mutual consent that diameter of ALCMs would be larger than diameter of SLCMs and their launchers.

Control over amount and deployment of cruise missiles is also obfuscated by the fact that in contrast to production plants of ICBM and SLBM which are well known, recognized and identified by the parties, analogous objects of SLCM (normally, aircraft factories) have no visual distinctive marks. Location of SLCM storage sites is much more complicated issue. A number of independent experts estimating effectiveness of mutual control over SLCMs consider different variants of monitoring. A "minimum verification" variant is based on sharing of information between Russia and the US about presence of SLCMs, amount of produced and deployed missiles at each ship and submarine. The same procedure as for SLBMs. Obtained data is supplemented by information received from space-based observation systems.

However, in this case the most serious problem is still distinction of nuclear and conventional warheads. Solving of this problem is somewhat simplified by the fact that Russia and the US undertook obligations in 1991 to remove all tactical nuclear weapons from ships and submarines and only conventional cruise missiles may be deployed there. All nuclear SLCMs must be placed in coastal storages. Limited number of inspections may be conducted under coordinated proposals on quantitative control over SLCMs, just like START-1 treaty for nuclear cruise missiles.

"Intermediate verification" variant provides considerable part of information of SLCMs to be obtained by supervision over their production and maintenance sites. In this case any SLCM should be disposed only in the presence of another party's inspectors. Inspections should be conducted in missile production sites as well as in maintenance areas. Each missile made must be marked for further identification. This variant of control does not provide regular inspections of ships, submarines and naval bases. Supposedly, information about amount of SLCMs on each ship would be checked by national facilities.

A "maximum verification" variant provides inspections of ships and submarines as well as monitoring all stages of SLCM lifecycle, from production till withdrawal from service and subsequent disassembly. This variant was proposed by the Soviets as early as during START-1 negotiations. However, the US party did not consent to apply that variant. According to it, primary objects of control over SLCMs are their sites of production and mounting warheads, where each cruise missile should be marked and sealed. Inspectors are supposed to work in ports and supervise loading of CMs on board ships. In this case deployment of SLCMs is reasonable to limit by two types of submarines and one type of surface ship. It is also provided to conduct limited number of inspections at other ships to verify absence of SLCMs.


Alongside with that the experts have to accept the fact that even on-site inspections will not entirely prevent possible violations like following ones: a number of SLCMs produced may not be declared; there may be a secret missile production established; conventional SLCM warheads may be secretly replaced for nuclear ones. However, considering various inspection techniques over nuclear arms, Russian experts have reached a conclusion that there are objective possibilities for remote detection of shipborne nuclear SLCMs.

Technical fundamentals to prove this hypothesis were results of joint Soviet-American experiment on detection of nuclear munitions at cruiser Slava. During the experiment held in Black Sea in July 1989 the Americans used an instrument with gamma ray semiconductor detector on basis of high-purity germanium crystal with energy resolution about 2 keV. The detector was placed just on the launcher. In 10 minutes they obtained radiation spectrum with peak values typical for different isotopes of uranium, plutonium and some of their degradation products; that fact confirmed presence of nuclear warhead. Test results showed that using this method it is practically impossible to obtain any information of warhead design; both sides were quite satisfied with that.

Soviet experts offered helicopter-borne system Sovetnik to be used in the experiment. The system was designed in Kurchatov Institute of Atomic Energy and based on neutron detector which registered neutrons ejected as a result of spontaneous fission of plutonium-240 used as an additive to weapon-grade plutonium. The neutron detector was mounted on the deck-based helicopter performing slow flyover of inspected ship. Presence of nuclear munitions aboard was proved if the neutron detector's indication was higher than a certain threshold considering distance to the ship, expected background fluctuations and other potential uncertainties of statistical and nonstatistical nature. The instrument provided neutron flux registration at distance up to 100–150 meters, although highest detection probability of nuclear warhead (about 95%) was recorded at distance up to 30 meters.

Efficiency of Sovetnik system had been previously tested during actual tests conducted in Black Sea and Mediterranean Sea in 1978–1979. Following US ships were checked by the system then – frigate Truett, aircraft carrier America, destroyer Barry, transport vessel Mount Baker. Nuclear munitions were detected on some of them. In this regard one should emphasize that in future Sovetnik system could be a component of SLCM remote monitoring system.

The experiment at Black Sea became a significant milestone on the way of establishing transparency and mutual confidence between Soviet and American scientists. It demonstrated real possibility to achieve desired level of voluntary trust and openness between leaders of the two countries, even in such sensitive area as nuclear arms. It remains to hope that at forthcoming Russian-American talks on strategic nuclear weapons both parties would draw on experience to achieve positive results, including such topical issue as control over long range sea- and air-launched cruise missiles.

Source:, Author: Vladimir Semyonovich Belous – chief researcher of International Security Center of Global Economics and Foreign Affairs Institute of the Russian Academy of Sciences, Gen. Maj. retired. 20.11.09

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