The world is now entering a new era. A key question when considering arms limitations proposals and future strategic force structures is how many submarines armed with strategic weapons (SSBN’s) the United States should have. The INF Treaty actually decreased the types and numbers of intermediate range nuclear weapons and their delivery systems in Europe. The portending Strategic Arms Reduction Treaty, START, promises to follow the path of the INF Treaty to reduce the numbers of strategic weapons significantly. Caps of 6,000 missile warheads are discussed – roughly half the number of those now deployed by the United States. Henry Kissinger reports our initial START Proposals suggest we have 18 SSBN’s, each with 24 tubes and each missile canying 8 warheads (3,456 warheads). But this number was determined by arms control advocates who took present missile force distribution and simply divided by about 2. It bears no relation to what will be needed if the whole United States strategic force posture is examined.
Twenty-nine POSEIDON Class submarines and eight TRIDENT Class submarines carrying 656 missiles with about eight thousand warheads are now in commission. This year the fifteenth TRIDENT Class submarine was authorized. The reported present Navy program is to build one each year until 24 to 40 TRIDENTS are in operation. Forty would be an enlargement of the original program of about twenty SSBN’s.
The concern usually voiced about the needed number of these submarines centers on their survivability. There is general consensus that the number of submarines must not be less than some minimum which ensures the continued perception of the systems’ assured and unacceptable destruction of the enemy’s homeland assets. There must be sufficient numbers also to ensure that an enemy’s best ASW efforts cannot attrite SSBN’s below this minimum. Perception is the key perception by both sides; the United States and the Soviet Union. The reality is simple. There is no significant threat to the US SSBN now and no realistic threat appears on the horizon.
Submariners recognize that advances in oceanography, suGmarine design and acoustic processing have resulted in a more favorable situation for the SSBN – not a more threatening one. The advantages gained by nuclear propulsion, sound quieting, electronic countermeasures and similar developments have given U.S. submarines greater and greater advantage over their opponents, including their submarines. For SSBN’s with no need to close their targets and which can evade at will, these advantages are unbeatable. Panels of scientists who examine this subject have become more and more positive in their statements that this situation has little probability of changing. To create a significant change requires not just enemy resources and engineering. Apparently, new physical phenomena must be discovered before these conditions will be altered significantly.
Even though no developments can be foreseen which will threaten a strategic submarine force of any size – even one as small as the French or British — some minimum number of submarines is required by those countries in order to continue to convince a potential enemy that none of his efforts can compromise the survivability of the country’s strategic submarine force. The number of submarines at sea must be high enough to deny success for any concentrated short term ASW effort. What constitutes that total number is not clear. But the number is probably smaller than that which will be required for reasons other than perceptions as to the ASW threat posed.
The consideration which should determine the number of fleet ballistic missile submarines eventually deployed is the number of nuclear weapons the American political leadership believes to be adequate to deter the Soviets from starting a war. Submariners tend to think only about the ASW issue because that is where their expertise lies. Arms control limits get the publicity. Yet it is the size and characteristics of the total US strategic forces (the TRIAD) that will deter the Soviets, which should be the determinant of how many and what kinds of strategic forces the United States should have.
The popular methodology used to determine adequacy of strategic forces is to compare numbers of warheads and delivery systems on each side. But that has meaning only when these weapons are aimed at each other. Submarinebased weapons cannot be attacked and their weapons are aimed at targets other than enemy submarines. The number of submarines the United States should have has no relation to the number the Soviets have but rather relates to American beliefs as to what forces will deter Soviet aggression and nuclear war- and what other forces exist in the United States’ arsenal to achieve these political aims. In the past, considerations of assured deterrence and survivable· force structure have not been very important because force levels were over-subscribed. There were more than enough nuclear weapons. Both the Navy and the Air force were encouraged to build forces to suit their own concepts without much concern. So warheads proliferated in accordance with service desires and designs.
This situation has changed. Arms limitation agreements, budget constraints and political objections to basing are changing the nature and size of strategic forces which Americans are willing to build. Politicians who formerly could be characterized as generally favoring nuclear weapons as a cornerstone of defense because of their low costs now see increases in · numbers of nuclear weapons as politically undesirable and economically impractical. An almost certain outcome of these pressures will be fewer nuclear weapons in the future than we have had in the past.
In the circumstances where there are fewer weapons, each individual weapon is more valuable than it was when there were plenty of them. (The adage is as true for torpedoes in a “target rich patrol zone” as it is for nuclear weapons.) Weapons systems which are hardly wlnerable to destruction become even more important in a period when there are few weapons rather than in an era of “weapons plenty.” The vigorous attempts to find a basing mode for ICBM’s, testify to the value of this attribute. Nuclear weapons at sea possess the characteristics of being non-targetable and covert in ways which cannot be matched ashore.
The difficulties encountered while trying to find a basing scheme which would provide the MX ICBM some degree of protection against a first strike, testify to the increasing importance of systems based at sea. Strategic policy reservations working against land-based missile forces were expressed in the recent Report of the President’s Commission on an Integrated Long Term Strategy for discriminate deterrence. This Commission condemns any reliance on Launch Under Attack. Without the ability to be launched while under attack, fiXed forces are hostages to a first strike. Thus the Commission’s proposed policy questions the worth of land based strategic nuclear forces and concomitantly increases the value of survivable at sea strategic forces. The debates over railroad and road mobile basing of ICBM’s demonstrate how difficult it is to create conditions ashore that equate to the natural inwlnerability of sea based forces.
As the numbers of weapons decrease and the potentially survivable Soviet targets increase, those which cannot be destroyed during an intercontinental exchange or are not used in an immediate retaliatory attack increase value exponentially; their value rises disproportionately faster than their numbers alone seem to warrant. The focus on reserve weapons in seabased platforms which can endure for a prolonged period, even in a nuclear war, will continue to grow. They have a robustness and endurability which cannot be duplicated ashore.
Over the past few years the prominent argument advocating ICBM’s has been a perceived need to threaten extremely “hard” targets. i.e. heavily fortified silos and command centers. With the advent of the TRIDENT D-5, sea based missiles will have the accuracy and yield to attack most kinds of target. With the deployment of D-5 in 1989, this last argument which has justified land based strategic systems disappears.
Basing nuclear weapons at sea allows the country and its political leadership to avoid the political costs associated with basing schemes for weapons ashore. Though debates will continue, the creation of defense mechanisms to improve ICBM and bomber survivability – to buttress the arguments for land based forces — are not likely to convince the political opposition. Political costs for land-based weapons are now very high. Finding a new ICBM basing mode which is politically acceptable seems to be unlikely and, as bomber costs rapidly escalate, opposition in the Congress and the country grow, and sea-basing of strategic weapons become even more attractive.
Finally, the American public supports sea-based nuclear weapons and this public support appears likely to increase. Since the political costs associated with sea-based systems is small, their importance in the entire US force structure is likely to grow. This effect can be seen in the 1988 Democratic platform which endorsed TRIDENT D-5 while questioning the modernization for both the ICBM’s and the bombers. This public acceptance will accentuate the other influences enumerated above in making the Navy’s role for strategic forces more significant in the future than in the past.
In summary, deterrence requires having enough weapons deployed in such a manner as to provide an unacceptable threat to the targets deemed to be those which will dissuade the Soviets from using their strategic weapons. Since there appears to be no realistic way to gain additional political leverage from land-based strategic weapons, a continuing shift of strategic weapon capability to submarines is likely to take place without any effort or encouragement on the part of the Navy.
In this context, the number of SSBN’s needed should be determined by considerations of national policy relative to an adequate strategic weapons structure. These considerations invulnerable bases, second strike capability, substantial reserve forces, realization that other own strategic forces are not likely to be built or sustained – should establish the number of weapons which will have to be deployed in submarines. More strategic submarines will be required to fulfill these needs than will be required to ensure the perception of invulnerability of that force. Twenty TRIDENTs (3,840 warheads) will not be enough.