Document created: 18 June 04
Air University Review,
January-February
1970
The United States has for some time followed
a second-strike assured-destruction strategy in planning and developing its
strategic military forces vis-à-vis the Soviet Union. This strategy
provides the U.S. with a deterrent capable of surviving a Soviet pre-emptive
counterforce attack on the U.S. strategic offensive force (SOF) in sufficient
strength to be able to respond with a countervalue attack on Soviet targets
that would result in unacceptable damage to the Soviet Union. The SOF structure
was designed to provide such a large number (1000) of hardened Minuteman silos
that it became virtually impossible for a Soviet pre-emptive attack on them to
so degrade the U.S. response as to make the resulting damage acceptable to the
U.S.S. R.
The introduction of multiple independent
re-entry vehicle (MIRV) payloads on Soviet missiles may present problems to the
survivability of the U.S. SOF. It may become possible that a sufficiently
massive pre-emptive attack could be mounted against the Minuteman force to
damage it too severely to enable the force to retaliate effectively. Whether or
not such a situation would ever exist, it certainly is a possible threat which
the United States must consider in its force planning. A U.S. force equipped
with MIRV would require fewer surviving missiles to inflict the necessary
retaliatory damage. Still, a multiple-payload missile attack could be so heavy
as to reduce even such a MIRV force below what is considered a necessary survival
level.
Several responses are available to the U.S.
should it be felt that a pre-emptive counterforce attack would destroy too
great a portion of the SOF, including:
1. Proliferation of the SOF in order to have
a greater number of them survive, taking the form of additional fixed or mobile
land-based missiles, or additional sea-based missiles, carried in either
submarines or surface ships; or an increase in the payload of individual
missiles.
2. Further hardening of missile silos.
3. Terminal antiballistic missile (ABM)
defenses for the land-based missiles.
4. Combinations of the above procedures.
These possible U.S. responses could have
serious undesirable effects. They are likely to trigger increases in the level
of Soviet forces, thus initiating another round in the arms race. Furthermore,
they will not remove the temptation for a pre-emptive first strike; they will
merely increase the destructiveness needed for such a strike to succeed.
Although economic constraints will eventually put a ceiling on the nuclear
armaments each side will deploy, it would nevertheless be worthwhile to examine
the alternative approaches for maintaining a credible United States deterrent
through an assured-destruction capability.
Clearly, it becomes desirable to maintain the
U.S. assured-destruction capability by other means, means which do not
proliferate U.S. forces and thus do not generate Soviet responses that would
further proliferate their forces but which would reduce the attractiveness of a
pre-emptive counterforce first strike on the U.S. One method to achieve these
objectives is to adopt publicly a policy of launch on warning1 as a
U.S. response option.
A policy of launch on warning can be fraught
with danger unless it is circumscribed by a set of rules and safeguards which
clearly indicate that it is not simply a pseudonym for pre-emption by the U.S.
and thus a destabilizing policy. Within this broad framework, let us examine
the rationale for such a policy.
launch on warning
Simply stated, a policy of launch on warning
means that when there is incontrovertible evidence of an attack under way which
is sufficiently massive to jeopardize the U.S. second-strike
assured-destruction capability, the SOF will be launched prior to the arrival
of this attack. While such a policy requires knowledge of the characteristics
of an attack, as well as the perfection of command and control procedures,
these requirements are believed to be achievable. By eliminating the
attractiveness of pre-emptive attacks, the policy should tend to stabilize the
strategic balance, especially since its bilateral adoption would serve as an
effective deterrent. Under such conditions, the impetus for proliferating
offensive forces would be removed, and the mutual reduction in offensive forces
might become more acceptable.
Objections to a policy of launch on warning
(even when all the required safeguards are attached to it) may be made on
various grounds, including moral, legal, political, strategic, and technical,
with considerable overlap among them. It is believed that most of these can be
overcome and that the remainder can, on balance, be tolerated.
The launching of missiles against another
country is certainly a hostile act, in particular when the number of missiles
launched is sufficiently massive to seriously threaten the attacked country’s
force structure. In more specific terms, in case of a pre-emptive counterforce
attack on the U.S. SOF the number of threatening objects required to jeopardize
the U.S. second-strike assured-destruction capability is clearly going to be
large—at least in the hundreds, more likely in the thousands. The collateral
civilian casualties resulting from such an attack have been estimated in terms
of tens of millions in the absence of fallout shelters. It seems specious to
argue that the U.S. should absorb such an attack before retaliating. There are
legal precedents for retaliation after the initiation of an attack, without
waiting for the effect to be absorbed.
The collateral civilian damage that would
accompany a massive Soviet pre-emptive counterforce attack on the U.S. would be
sufficiently high to set in motion countervalue retaliation, as has been stated
on numerous occasions by responsible U.S. officials. The whole concept of
deterrence rests on this foundation. It would be absurd in such a case to await
the outcome of the first strike on the U.S. before counterattacking.2 What
is important is to maintain deterrence by adopting policies which will remove
all temptation for pre-emptive counterforce attack on the U.S. Launch on
warning would emphasize the futility of such an attack, regardless of its size.
The political difficulties of adopting a
policy of launch on warning seem to center on the potential hostile
interpretations that could be placed on it. Propaganda attacks on this policy
are to be expected, once it is publicly adopted. These attacks would likely say
that the policy is a cover for the U.S. advocating something akin to a
pre-emptive policy of its own or that it means that the U.S. is adopting a spasmodic
response policy. The first charge can be readily refuted for two reasons: it is
quite likely that the U.S.S.R. would respond in kind to a U.S. pre-emptive
counterforce attack;3 and should the U.S. seriously contemplate
pre-emption as a viable policy, adoption of launch on warning would have no
effect on it.
The question of spasmodic response is more
difficult to explain, since the whole concept of an assured-destruction second
strike is basically of this kind. The whole problem becomes one of detecting
the impending attack, identifying the attacker, and assessing the magnitude of
the attack, to determine whether it threatens the assured-destruction
capability, before ordering a launch. Thus, the solution of the problem is a
matter of technology, which must also have provided the necessary command and
control system for timely implementation of the decision.
Obviously, extreme reliability in all these
procedures is required. It is believed that the presently available detection
and identification means are sufficient to deal with a potential Soviet threat.
As yet, there are no meaningful threats to the survival of U.S. second-strike
capabilities from other countries. It is reasonable to expect that, by the time
such threats could develop, improvements in technology will enable the positive
identification of any attacker. Thus the possibility of a misdirected attack on
warning would be no greater than if the counterattack were launched
after arrival of the pre-emptive attack on the U.S. It is obvious, however,
that as the number of countries capable of meaningful attack on the U.S. SOF
increases, the problems of identifying the attacker(s) and the means of
responding to attacks will be vastly increased. This holds true whether or not
a launch on warning policy is adopted, and it simply emphasizes once again the
political-strategic problems associated with the horizontal proliferation of
strategic nuclear missiles.
There is some definite threshold above which
a pre-emptive attack would threaten the SOF’s capability in a second-strike
assured-destruction role. This threshold value can be influenced by the
characteristics of the SOF, of the attack on it, and of the Soviet target
complex and its defenses. Because of uncertainties in many of these characteristics,
it is not wise to attempt to select a specific threshold value above which a
launch signal would be given. It would be sufficient simply to articulate the
policy that any attack which would threaten the U.S. second-strike
assured-destruction capability by reducing it below an unspecified level would
trigger a U.S. launch before the SOF is actually damaged. A policy of launch on
warning should in no way change the U.S. response to what is clearly an
isolated accidental or unauthorized launch of one or a small number of
missiles. This is the type of attack which a light ABM system is meant to cope
with.
Several steps are available which would
further lessen the likelihood of a spasmodic response prior to the arrival of
the pre-emptive counterforce attack on the U.S. Launching on warning could be
limited to such a number of U.S. missiles as to guarantee that these missiles,
together with the surviving withheld missiles, would provide the
assured-destruction capability. (In calculating the required number of
surviving missiles, the change in effectiveness of an enemy’s ABM system
against attacks smaller than full-scale must be considered.) The launched
missiles could be equipped with means of self-destruction in flight, should the
expected attack not materialize. Obviously, these would be expensive steps;
they would also reduce the size of the SOF until the launchers could be
reloaded.
Let us assume that the U.S. considers it
essential that 300 Minuteman missiles be available for launch as a second
strike. Let us also assume that a Soviet pre-emptive counterforce attack would
be 85 percent effective, leaving only 150 potential survivors from the original
1000. If the U.S. were to hedge and launch 200 missiles upon identifying the
attack as one so large as to reduce its second-strike force below the
acceptable level, then the withheld force could still be expected to have 120
survivors. Should the attack not materialize, the 200 missiles could be
destroyed in flight before they pass beyond the North American continent. The
remaining 800 Minuteman missiles would still provide a deterrent; in case of a
second attack, they would have to be launched when the detected second attack
is large enough to threaten the survival of 300 Minuteman missiles.
Another means of reducing the attractiveness
of pre-emptive counterforce attack on the U.S. is to replace fixed land-based
missiles with mobile sea-based missiles. The replacement could be accomplished
without increasing the total U.S. payload, and from this standpoint it could be
considered not to be destabilizing. Bilateral adoption of such basing has been
advocated as maintaining mutual assured-destruction capabilities without
providing incentives for either side preempting. Arguments against conversion
of the U.S. SOF to an all sea-based force would probably center on the
possibility of hidden vulnerabilities of a force composed of only one type of
weapon system deployed in a relatively small number of ships, and on the added
expense over land-based missiles.
The risks, advantages, and technological
problems requiring solution for adopting a launch on warning policy are listed
for ready reference.
risks
Among the technical, strategic, and moral
risks are the following;
False alarms. This risk is probably regarded as the major
one. It is certainly not possible to guarantee that false alarms will not
occur. It does appear possible, on the other hand, to reduce the likelihood of
their occurrence to a very low level, by the use of multiple redundant sensing
techniques. In the event that a false alarm would result in the launch of U. S.
missiles, it would still be possible to announce that the missiles were
launched on warning and that, if the warning was false, they will be destroyed
in flight before they pass beyond a specified line (e.g., over North America).
Condemnation of U.S. as callous and playing
with fire. In response to
this charge, it can be pointed out that adopting a launch on warning policy was
publicly announced to emphasize the futility of pre-emptive counter-force
strikes on the U.S. SOF. To the extent that the policy strengthens the U.S.
deterrent by introducing additional risks for a potential attacker, it is no
more callous than threatening a would-be attacker’s viability as a
twentieth century nation.
Loss of flexibility. Launch on warning would dictate that the U.S.
response be a countervalue one, both in order to deter and because it is
unlikely that the U.S. missiles could be retargeted in time to take into
account the attacking missiles. The U.S. policy of flexible response, with
which launch on warning would have been incompatible, has apparently been
replaced with one of assured destruction,4 with which launch on
warning appears to be compatible. The loss of operational and targeting
flexibility which could result appears to be a price worth paying for the
additional deterrence provided.
Vulnerability of the launched missiles.
U.S. missiles in their silos are less
vulnerable than during their boost phase; and although it can be argued that,
once launched, they may be attacked in flight by some of the arriving missiles,
it is unlikely that the attack could readily shift from silos to missiles in
flight. Moreover, the attacker will not necessarily know which portion of the
U.S. missiles will be launched on warning, so the defense has some latitude in
avoiding the attack.
Expense. If, as is suggested here, additional expenditures are incurred for the
multiple redundant sensors to reduce the likelihood of false alarms, plus
additional expenditures to insure more reliable command and control systems, it
may be argued that these sums take money away from the development and
procurement of weapons. In other words, they do not increase the U.S. strategic
capabilities. At the same time, the incorporation of self-destruct mechanisms
into missiles is expensive in terms of cost, payload reduction, and
reliability. Once again, it seems that this is a price worth paying, since it
would lessen the need for additional rounds of weapon acquisitions.
advantages
A launch on warning policy must offer
sufficient advantages to justify the risks and added cost. Among these are:
1. Reduced likelihood of a pre-emptive
counterforce missile attack on the U.S. Launch on warning would negate the
success of such attacks regardless of their size, thus reducing the temptation
for pre-emptive tactics.
2. Increased risks to an attacker, by increased uncertainty about the level of attack which will result in a U.S. launch on warning.
3. Reduced temptation to pre-empt and
consequent reduction of incentives for an offensive arms race.
4. Inducement of symmetrical, or perhaps even
asymmetrical, arms reductions.
5. Tendency of adversaries to insure tighter
command and control procedures in view of the increased risks of retaliatory
response.
Technological problems
In order to apply a launch on warning policy
successfully, several matters related to technology need improvement, and
changes to certain capabilities and systems must be introduced.
1. An extremely high-confidence threat
detection, identification, and assessment system to reduce to a minimum the
possibility of false alarms. In order to achieve the high confidence levels
needed, it is likely that multiple, redundant sensing systems will be needed.
These are likely to include over-the-horizon radars, early-warning radars, and
optical systems. The systems are likely to be ground-based, satellite-borne,
and possibly shipborne and airborne.
2. The threat identification and assessment
system must be coupled with a command and control system capable of making
rapid decisions and implementing these in extremely short time. Should the
threat be sufficiently massive that a portion of the U.S. missile force is launched
on warning, it may be necessary to communicate this fact to the U.S.S.R.,
together with assurance that these missiles will be destroyed in flight, should
the alarm turn out to be false.
3. A missile destruct mechanism must be
installed to be used in case of launch in response to a false alarm. This
mechanism must be controlled from U.S. control centers and must be both highly
reliable and tamperproof.
It is believed that publicly adopting a
policy of launching U.S. missiles on warning of an attack sufficiently large to
jeopardize the ability of the surviving strategic offensive force to inflict
unacceptable damage on the attacker will be a useful strategy for the following
reasons:
1. A launch on warning policy makes a
preemptive counterforce first strike upon the U.S. unattractive, since the
attacker cannot be sure of thwarting an assured-destruction second-strike
response. Thus the nation’s second-strike capability need not be increased in
order to provide a sufficiently strong surviving force.
2. The characteristics of the SOF are such that
a launch on warning can be implemented. This option is already available to the U.S.,
but it is believed that adopting such a policy would increase the credibility
of the U.S. deterrent.
3. The launch on warning policy could, in
addition to lessening the likelihood of an arms race, provide a means for
reducing the size of the U.S. SOF and, reciprocally, the size of the Soviet
strategic offense capability.
4. Improvements in the ability to detect and
identify attacks and in the command and control systems for the SOF would aid in
carrying out the policy. Such improvements could be financed from funds that
would otherwise be devoted to the development and deployment of new systems.
5. The potential for stability in U.S.-Soviet strategic offense structures, brought about by removing the temptation for a pre-emptive counterforce first strike, outweighs the potentially adverse criticisms of a launch on warning policy.
6. The uncertainty of the threshold at which a
pre-emptive attack would trigger a responsive launch adds to the deterrent
provided by the launch on warning policy.
It should be noted that an announced policy
of launching U.S. missiles prior to the impact of attacking missiles will
discourage a Soviet pre-emptive counterforce ICBM strike. There are other types
of attack that could endanger our assured-destruction second-strike capability.
Examples include attacks by submarine-launched ballistic missiles, a greatly
improved antisubmarine warfare capability that could destroy a high proportion
of U.S. SSBN’s (nuclear-powered launch vehicles for Polaris missiles) with high
confidence, and a large-scale ground assault on the Minuteman force, which
could achieve similar results. Any U.S. policy that would discourage
pre-emptive ICBM attacks could be said to encourage such actions. Providing
increased protection to the U.S. SOF against non-ICBM threats would appear to
be feasible at lower levels of expenditure, and certainly without intensifying
the arms race.
Washington,
D.C.
Notes
1. The policy of launch on warning considered in this discussion must be differentiated from that which governs the launch of a missile force deployed in soft launch sites. One of the serious drawbacks of the first-generation U.S. intercontinental ballistic missiles was their vulnerability on the ground, coupled with the rudimentary warning system available and the long time required to launch the force. Under such conditions it became necessary to initiate the launch sequence upon receipt of the slightest warning. Today we have a much more numerous force, deployed in hardened and dispersed silos, a highly sophisticated detection system, and missiles capable of being launched in a very short time. Perhaps a better term for the policy discussed here would be “modified launch on warning.”
2. The purpose of a launch on warning policy
is to insure that the U.S. assured-destruction potential is preserved; so it is
important only to indicate the intent to launch the missiles targeted
for countervalue attack before the U.S. missiles are destroyed in their silos.
Should such a situation ever arise, deterrence will have already failed, and
simultaneously attacking empty Soviet silos would not make any significant
difference.
3. Because of technical considerations, it is believed that the U.S. SOF, consisting primarily of short-reaction-time solid-propellant missiles, is in a better position to launch an attack of its own after identifying the launch of a massive Soviet attack. The launch on warning option has been available to the U.S. since the deployment of Minuteman missiles; however, such a policy has not been publicly stated.
4. The U.S. assured-destruction policy
threatens a countervalue retaliation in the event of a massive attack on the
U.S. SOF.
Robert I. Widder (B. M. E., Cornell University) is Senior
Research Engineer, Battelle Memorial Institute, Washington, D.C. After serving
with the Army during the World War II, he held various engineering positions in
the aerospace industry until assuming the present position in 1964. At Battelle
his research has centered on the technical, economic, and strategic aspects of
arms control, advanced weapon systems, and air-cushion vehicle transportation
systems. Mr. Widder’s writings have appeared in Systems Designer’s Handbook
and U.S. Naval Institute Proceedings.
Disclaimer
The conclusions and opinions expressed in this
document are those of the author cultivated in the freedom of expression,
academic environment of Air University. They do not reflect the official position
of the U.S. Government, Department of Defense, the United States Air Force or
the Air University.
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