There seems to be some discomfort in accepting the increasing importance of submarines in future sea wars, and their ability to cany out their assigned missions. In addition, there is a pervasive wony about war in general and the danger that any war can escalate to the use of nuclear weapons. Given such observations, it is appropriate to first look at the capability of the theater submarine, SSN or SS, in a nuclear war environment; then to examine the probability of a theater nuclear war-at-sea.
How effective is the theater submarine in a nuclear war environment?
To understand this, there are three major categories of factors to consider: the operational capabilities of submarines which may use either conventional or nuclear weapons in nuclear war; the effects of nuclear weapons which can impinge on those submarines at sea; and the nature of nuclear ASW.
Because the strongest foundation of deterrence is a credible war-fighting capability, and because the concept of deterrence includes the discouragement of escalation at all levels of conflict (with an implicit linkage from one level to another), the operational capabilities of each and every U.S. force, visa-vis its opponents, form an armor of deterrence with which the United States protects its citizens and interests and supports its allies in their security pursuits. It is thus those operational capabilities of submarines in a theater nuclear war that form one of the strongest Hnks in the deterrence of that level of conflict. And, since nuclear war most probably will happen at sea if it breaks out anywhere, the submarine potential for deterrence of any nuclear war – at sea or ashore — should help deter any superpower hostilities.
Deterrence by any force has to be posed both before hostilities start, and during any phase of conflict which can lead to full engagement. Importantly, most modem U.S. theater nuclear naval forces are dual-capable in that they can participate in both conventional and nuclear weapon encounters. By viable participation at lower levels of violence, while remaining ready to fight at the higher levels. they contribute to deterrence at both levels of conflict. Significantly, the operational capabilities of theater submarines are uniquely suited to that deterrent posture — with their potential to fight effectively at both the conventional and nuclear level.
Those capabilities have to show two simultaneous faces: the ability to deliver punishing damage, and the strength to withstand the damage which the enemy is capable of inflicting. An ideal naval force in a theater nuclear war should therefore feature stand-off weapons of over-the-horizon cruise missiles or possibly ballistic missiles and very long range torpedoes, all launched from undetectable platforms that can survive relatively close-aboard bombardment explosions and out-run homing weapons. These are characteristics inherent to attack submarines maintained at the leading edge of technology.
Obviously, the question of gaining these warfare characteristics with modem SSNs or with up-to-date carrier battle forces is one of money and resource allocation. Significantly, the strength of a CVN or a modem CV is itself a powerful deterrent to any war-at-sea. When it comes to actually fighting a theater nuclear war, however, it stands to reason that the U.S. theater submarine should be the preferred platform to carry the war to the Soviet fleet, simply because of its hardness and stealth attributable to being submerged. In addition, the allocation of resources has to consider the probable conditions of such a battle at sea. As most planners now see the at-sea situation, it would be a U.S. ASW action against Soviet submarines attempting to interdict the SLOC’s in the open ocean and a U.S. submarine action against the Soviet surface fleet, theater submarines, and strategic submarines in their “bastion” areas. It would seem, therefore, that if the threat of theater nuclear war-at-sea can be considered real to any extent, the resource allocation scales should be tipped to the attack submarine components of the future U.S. fleet, as it has been done in the Soviet Navy.
Since credible survivability is so important in this context, the effects of nuclear weapons in a very general way at least need to be looked at. These are usually considered to comprise blast, radiation and heat. As far as submarines are concerned, the attenuation properties of sea water mitigate both radiation and heat effects. Blast has always been considered the critical factor in nuclear ASW, with overpressures and shock being-means of concern. There is no intention to minimize these effects on submarines, but it is appropriate to emphasize that a modem submarine is a very tough structure, and its water environment is one that permits translation with force, rather than upset like a highway truck in a hurricane. In the same manner that overpressure can be addressed in the design of a submarine and its systems, shock forces can be taken into account in its mechanical equipment foundations and the internals of electronic systems. In short, while direct hits will continue to be bad news, the near miss distance for a disabling shot on a submarine tends to be far less than on a surface ship or aircraft.
Two other effects are of concern to the theater nuclear warat-sea forces. EMP, or electro-magnetic pulse, is a phenomena caused by exo-atmospheric nuclear bursts which generate large electrical currents in bodies which act as antennae. A nuclear weapon detonation over Sicily, for example, could cause currents in shipboard systems which could critically damage every unprotected naval computer between Gibraltar and Israel, and seriously affect all communications except the lowest frequency ones. The submerged submarine however rarely presents an antenna susceptible to EMP effects and requires very few external communications to function properly — while the necessary transmissions to submarines of very low frequencies are basically hardened against the effects of nuclear explosions. The other effect of a nuclear weapon which needs to be recognized is the noise generated by an underwater nuclear explosion. The reverberations within the ocean caused by a nuclear underwater blast are likely to be overwhelming as to sonar use, but there are variations in this effect due to basin geography, size of warhead and water conditions. Yet, a useful rule of thumb is that the bigger the ocean and the further away the detonation is, the less effect that it will have on the sonar performance of a submarine. It is a problem, but it is probably not disqualifying to a competent submarine’s ASW effectiveness. It may even serve to mask the sonar performance of an enemy’s countermeasures.
The third major category of effects from nuclear explosions has to do with the nature of nuclear ASW, or the realities of bow submarines can be attacked with nuclear weapons. In ASW the kill mechanism is one-half of the problem. The tendency, in considering nuclear ASW, is to assume that the lethal radius of the weapon will make up for inaccuracies in localization of the enemy submarine by the detection system employed. That may not be a valid assumption. ASW weapons are basically depth bombs or homing weapons. Depth bomb attack is inherently more inaccurate than attack with a homing weapon due to the potential for submarine movement during the firing approach to an assumed target position and the sinking time for the depth bomb to go to a lethal depth. Homing weapons, while being more susceptible to countermeasuring, however, have the potential to make up for fire control errors. If decoyed, moreover, a homing weapon is likely to be more traumatic to the hunter than to the hunted — if the homing weapon is then triggered closer to the attacker. Occasionally, ballistic missile attack is considered as a viable ASW killing measure. Although proposed as an anti-SSBN measure, it could be useful against theater SSNs or even SSs. The first problem is that ballistic missiles are expensive and may be husbanded – because of short supply due to arms control actions. The second problem with ballistic missiles in ASW is the unpredictable target travel during a relatively long time of flight, particularly if fired from shore emplacements.
It must be recognized that the much bigger bang available in nuclear weapons may not solve most of the problems inherent in any type of ASW.
The modem submarine can inflict heavy damage during a nuclear war-at-sea with both conventional and nuclear weapons. In addition, it can safely be said that today’s submarines have a significant potential for surviving in engagements in either level of sea warfare. It is therefore reasonable to accentuate the positive qualities of submarines in order to better assure their deterrence of nuclear war-atsea.
A number of capability enhancements can be postulated which should do that. Nuclear weapons employed for underice warfare make sense due to the ocean anomalies encountered in this environment and which affect homing weapon use. The most important enhancements however should be in the submarine platform itself. Keeping a force of submarines at the leading edge of technology will not be inexpensive, but it should suffice to hold an advantage in this most stressful naval situation – that of nuclear war at sea. Keeping that advantage is what will deter nuclear war. That seems to be a necessary step in the escalation process. A decisive submarine fleet may be thought of as a critical force with a deterrent warfighting value well in excess of cost and risk.
Although both submarines and nuclear war are subjects of general concern, it can be noted that understanding of the one operating as a vital part of the other is not high on the agenda of students of naval warfare. In fact, apart from a certain emotion which both subjects engender, the details of each are considered so arcane as to be difficult to understand. Therefore, one seldom sees them tied together for serious consideration as a credible influence on the outcome of a future war. There are two chains of logic which might explain this failure. On the nuclear side, there are many in the west who do not see the need for nuclear-equipped theater forces as well as strategic forces for the deterrence of war. There are also many who do not appreciate the importance of what happens at sea as well as from the sea. On the submarine side, some see the only tasks for western navies as the protection of the resupply lines to the Eurasian battlefields. In their view, the most logical use for submarines is as sophisticated ASW platforms for direct coverage of those SLOCs or to reduce the number of enemy submarines which might threaten high seas shipping. Others believe that the only job of navies is to provide a potential for shore strike and sea control, and submarines should merely offer an ancillary support as opposed to providing a major part of the shore strike capability and necessary sea control so that other forces can carry out their missions successfully. No matter what logic is used, submarine operations apparently remain much of a mystery because they take place outside the realm of instant intelligence and on-demand response to modem communications. As to a war at sea being possible between the superpowers, the likelihood is good because the superpowers have intersections of vital interests there and they have the available forces to fight each other. That conjunction of conditions is apparent in several areas of superpower competition – the eastern Mediterranean~ the northwestern Pacific, sometimes in the Indian Ocean and always on the northern flank of NATO. It can then be stipulated that a major war at sea is possible and the rationale for escalation to nuclear war should thus be examined.
The general case for escalation can be delineated in terms of vital interest$ which are at risk when conventional arms have failed to achieve desired war goals. In addition, there must exist a potential for answering an increased level of violence. Specifically, the incentives for either side to resort to theater nuclear force can be shown by using the northern flank of the NATO-Warsaw Pact confrontation as an example. If the Soviefs DELTA and TYPHOON submarines were put at serious risk by U.S. and other NATO SSNs the Soviets might escalate to nuclear war. They may also risk using nuclear weapons if they find themselves unable to prevent western aircraft carriers from coming to within strike range of the Soviet Union. In the North Atlantic, the Soviets may need to neutralize or delay the Allies’ resupply convoys to within the time constraints of the central front air-land battle action. It has to be noted that similar incentives to escalate can be expected on the NATO side. It should also be recognized that there can be a need to neutralize Soviet interdiction submarines on the Atlantic SLOC — should allied ASW fail or prove too slow. This could, for example, cause western Allies to use nuclear Fleet Air Defense weapons to protect logistic ships and Battle Groups from mass missile attack by land-based Soviet naval aircraft.
In addition to the various incentives to use nuclear weapons, the instabilities which may exist in the conventional battle and which might hasten the move to a higher level of violence, must also be considered. A force asymmetry is one type of wartime instability which can be due to one side not having enough in numbers of either platforms or required weapons, or by one antagonist not having sufficient speed, weapons capability or sensor effectiveness. It should be noted that one often cited instability is the assumed vulnerability of U.S. aircraft carriers to the nuclear-tipped anti-ship cruise missiles of the Soviet submarine force. However, it may well be found on closer examination that this instability does not actually exist. In fact, the toughness of large CVs and CVNs against conventional weapons may militate against the initiation of a war at sea, itself. A single hit in the hangar deck by a cruise missile with a 2200-pound warhead of high explosives might cause uncontrollable fires which could sink a carrier, whereas half a dozen torpedo bits might only slow it to 20 knots.
It is hoped that two points have been made clear: (a) that nuclear war at sea is quite possible and does not have to be closely coupled to a nuclear war on land; and (b) that dieselelectric submarines which can employ nuclear weapons will become more, rather than less, important in both alliance and national interests — as the threat of nuclear war at sea increases. But most importantly, the capability of a submarine, whether nuclear or conventional, to pose a threat of nuclear weapon attack is an important factor in the deterring of an escalation to nuclear weapons in a theater conflict.
James C. Hay