The essence of the matter is that American submarines are an effective deterrent to a Soviet attack on our cities, but are not a deterrent to an attack on U.S. armed forces. It is a sobering fact that if the USSR should launch a massive strike against our military installations, we could do little about it, short of a suicidal strike against Soviet cities, in the current state of disrepair of our strategic triad.
Experts count and recount missile silos, bombers, submarines, warheads, and megatonnage. They argue over whether we will have a kind of parity with the Soviet Union, in spite of the vulnerability of our ICBM’s and B-52’s. But there can be no argument about one basic fact: Soviet missile power has been growing faster than ours, and has succeeded in placing a large part of the American strategic deterrent at risk. The trend is frightening. If continued, it will lead to the possibility, a few years hence, of a preemptive Soviet attack aimed at the total destruction of American military power.
2. The Response
How is the United States to respond to this threat? One way would be by a massive build-up of our own missile forces, sufficient to match the threat of the Soviet ICBM’s on equal terms. The result would be a nuclear stand-off between two adversaries, each armed to the teeth, and each capable of delivering a knockout blow if it can get in the first punch. That would be a balance of sorts, but the balance would be unstable. There is a better way, and that is the way President Reagan chose in his speech on missile defense.
Suppose a brilliant inventor could devise a method to defend the United States against Soviet ICBM’s. Then our own ICBM’s—Minutemen and MX’s—would no longer be vulnerable to a surprise attack. These ICBM’s are accurate enough to destroy many hardened targets in the USSR, including the 700 hardened leadership centers sheltering the Soviet elite. If our missile silos were defended, Soviet leaders could not eliminate this threat to their existence by knocking out American ICBM’s in a preemptive first strike. If nothing else deterred the Soviet leadership from an attack on the United States, that circumstance would certainly do so.
Where can we find this invention? The answer is that we already have it. Critics of President Reagan’s plan spoke as if he were proposing a defense of entire cities and their populations, but he made no suggestion of that kind in his speech; and, in fact, such an “area” defense, while very comforting, would not be necessary at the start. For the protection of our Minuteman missiles, it is only necessary to establish a “point” defense—i.e., a defense of the few square acres surrounding each missile silo, and the small areas surrounding a limited number of communication centers, command posts, and other military installations. The means for such a point defense of critical military sites are in hand today. The basic technologies have been proven, they are inexpensive, and they can be put into use with relative rapidity.
The key to these technologies is the miniaturized computer. Extraordinary developments in the miniaturization of computer circuits enable millions of transistors and other electronic components to be packed into a space the size of a thumbnail. As a result, defense technicians now have the means for building elaborate computer brains into a very small missile—a mini-missile—so that it can steer itself toward its target. Sensing the target either by its delicate emanation of heat waves, or by its radar reflections, the mini-missile analyzes the product of its senses within its highly capable computer brain, and directs a succession of messages to small rockets arranged around its circumference. Delicate thrusts of these rockets steer the defending missile into the path of the oncoming ICBM warhead. The result is either destruction of the warhead by a direct impact, or an explosion of the mini-missile in the vicinity, releasing a cloud of flying metal fragments. The warhead, moving ten times faster than a bullet, tears into the cloud of fragments; the skin of the warhead is punctured in many places; its electronics are disabled; and the nuclear bomb inside it is disarmed.
In essence, the defense consists in tossing into the path of the speeding warhead some TNT and a keg of nails. What makes this simple defense work is its computer brain.
The amount of TNT need not be very large. One mini-missile of the kind described, currently being tested by the Army, contains less than 100 pounds of explosive. The reason is that the defending missile does not have to destroy the warhead to be effective; it only has to prevent the nuclear bomb inside the warhead from exploding. That happens to be fairly easy, because nuclear bombs do not go off very readily; elaborate arrangements and a great deal of fragile electronics are needed to make one explode. Accordingly, a small charge of TNT, or a cluster of high-speed metal pellets, will usually be sufficient to disarm the bomb’s mechanism.
In fact, it is not even necessary to keep the bomb from going off. Suppose, for example, Soviet technicians devise a countermeasure to the American defense by wiring the warhead so that the nuclear bomb inside it explodes automatically whenever a defending missile approaches. As long as that happens at a high altitude, far above the atmosphere, the effects of the explosion will not be very damaging at ground level, either in radioactive fallout or in blast damage. An altitude above 100,000 feet is sufficient to achieve this. Progress in developing the smart little missiles indicates that making the kill at altitudes above 100,000 feet is not an especially difficult task.
Thanks to the newest ultra-miniaturized computers, the defending missile can exercise a formidable amount of brain power. Suppose the Soviet technician tries to confuse our defense by arranging to throw off decoy warheads— lightweight imitations of the real thing. The decoys, necessarily thin and flimsy in their construction (if the decoy weighs as much as a real warhead, you might as well put a bomb inside), will tend to lose their heat more quickly than the real warheads as they fly through the cold of space. By the time the cluster of Soviet warheads reenters the atmosphere, the decoys will be appreciably colder than the real warhead. The brain of the mini-missile, analyzing these differences in temperature from one “warhead” to another, will have no trouble in telling the decoy from the real McCoy. And once the real warheads have been identified, the computers can even sense which warheads are headed for empty silos, and instruct their defending missiles to ignore these and concentrate on the warheads headed for silos still loaded with ICBM’s.
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This kind of technology is not visionary. Its important features are already in operational use in the Pershing-2 missiles being deployed in Europe. The warhead of the Pershing 2 contains a radar “camera” that looks at the terrain beneath it, compares what it sees with an image of the target stored in the warhead’s computer brain, and, guided by this comparison, changes its course and steers straight toward the target in the final moments of its flight. On the average, Pershing-2 warheads hit the ground within 30 yards of their targets, compared to an average error of 250 yards for the best missiles with old-fashioned dumb warheads. When the same kind of computer technology is used in mini-missiles for defense against ICBM warheads, the error comes down to a few yards, or even feet, or even inches.
Incidentally, the clever warheads on the Pershing 2’s explain the intensity of Soviet anger at the deployment of these missiles by NATO. Warheads of this kind, which can figuratively drop down the air vent of a Soviet command bunker, place at risk the military and political leadership of the Soviet Union—and they are the only weapons in the NATO arsenal with the accuracy and range required to do that. And being mobile, the Pershing 2 is also survivable; it cannot be entirely eliminated in a preemptive attack. These properties make the Pershing 2’s a very effective deterrent to a Soviet attack on Western Europe.
Getting back to President Reagan’s speech, one of the main criticisms of his plan was that a defense against ICBM’s can never be 100-percent effective. This criticism also applies to the smart mini-missiles. If these missiles were intended for the direct defense of American cities, they might not be of much value, because even a few ICBM warheads leaking through such a defense would kill millions of Americans. However, the situation is very d
ifferent when a defending missile is intended only for the protection of missile silos and other military sites. Suppose, for example, that the defense of the silos is only 50-percent effective—a conservative estimate for the technologies described above. This means that roughly half the attacking warheads will accomplish their purpose. Therefore, the USSR will be required to make its ICBM arsenal twice as big as it is today, to regain the level of threat it possessed before the defense was put in place. In other words, it will have to buy another ICBM for every one it already has. The Soviet Union has spent about $500 billion on the build-up of its ICBM arsenal over twenty years and might be hard-pressed to spend another $500 billion in a short time. Even if the USSR does increase its missile forces in an effort to overwhelm our defense, we can increase the number of defending missiles around each silo and once again reduce to an acceptable level the number of Soviet warheads that would reach their targets. This response is practical because each defending little missile costs considerably less than the warhead it is aimed at. Estimates by a team of scientists at Los Alamos indicate that if the Soviet Union tries to overcome an American missile defense by building more rockets and warheads, its costs will increase at least twice as fast as ours. In this situation, in which the ratio of costs heavily favors the defense over the offense, the Soviet Union may be led to rethink its whole strategy of striving for military dominance with weapons of mass destruction.
With the feasibility and cost-effectiveness, there is still the troubling possibility that a defense of our missile silos will be “destabilizing” and will undermine the policy of deterrence. According to this theory, which is held by a number of American scientists and arms-control specialists, the Soviets will perceive the defense of American silos as a signal that the United States is preparing to attack them, and is therefore protecting its military sites against the inevitable Soviet retaliation. Feeling nervous about that possibility, the Soviet Union will move quickly to attack us before our missile defenses can be completed. In other words, so the reasoning of the arms-control experts goes, a defense of American missiles brings the United States closer to war.
It seems to me, that nothing could be farther from the truth. As usual, facts determine the situation, and the main facts here are first, that the Soviets have many more ICBM warheads than we do, and second, that ICBM’s are the most valuable kind of missile from a military point of view, because of their great accuracy and ability to destroy hardened targets. (It is often mentioned that we have the same number of warheads, about 4,600, on our submarines as the Soviets have on their ICBM’s. However, the submarine-based warheads are inaccurate and have relatively low explosive power, about one-sixteenth that of Soviet ICBM warheads. Consequently, they are completely ineffective against Soviet missile silos, which are even more hardened than our silos.) We have 1,650 accurate Minuteman warheads, too few in number to do much damage to the several thousand important Soviet military targets, but the Soviets have at least 4,560 equally accurate and far more powerful ICBM warheads, that can do a great deal of damage to our military targets. If we lived in another world, in which the Soviet Union had not constructed all these late-model ICBM’s and many thousands of accurate and powerful warheads, an American system for defending our missile silos might be perceived as destabilizing and a weakening of deterrence. But in the real world, in which the Soviet missiles and warheads exist, an American missile defense restores our retaliatory force, and thus strengthens deterrence.
It is not clear why the Soviets have built up this mammoth ICBM force, because the build-up has been very costly—to repeat, about $500 billion over the years—and goes far beyond any reasonable level of military power they would need as a deterrent to an American attack. Whatever the reason, the fact is that they have done it. As a result, the Soviet Union is in a position to launch an attack on the United States aimed at destroying our means of nuclear retaliation—missiles, silos, B-52 airfields, submarine bases, and military command posts. In other words, those 4,560 accurate ICBM warheads look like the beginning of a Soviet drive to acquire a nuclear war-winning capability. We may not understand how the Soviets think they can possibly emerge victorious in a larger sense from a nuclear war in which they suffered “only” a few million to 10 million casualties, but apparently they do think that.
In any case, the USSR has built a large number of missiles and undermined our capability for retaliation and therefore our deterrent. Protecting our forces against the Soviet missiles will not give us a nuclear war-winning capability—the nuclear warheads of the Soviet Union are too numerous and powerful for that—but it will give us a continuing capability for retaliation against Soviet attack, which is the very basis of deterrence.
There are other gains for deterrence in a point defense against Soviet ICBM’s, in addition to the protection of our missile silos. The dish in California that receives the signal from our early-warning satellites can be protected. The communication lines that connect the President and top military commanders to the Minuteman launch-control centers can be protected. Our bomber airfields and submarine bases can be protected. Just two bases—one in Kings Bay, Georgia, and the other in Bangor, Washington—will support our entire fleet of Trident submarines. If these bases are undefended, half the Trident fleet—the part in port when a Soviet surprise attack occurs—must be written off at the outset. A point defense of the Trident bases against Soviet missiles will double the effective strength of the American submarine deterrent. (When there are only a few targets, and the destruction of each one is very important to the Soviet Union, it can always try to overwhelm our defenses by allotting a large number of warheads to each target. However, by the same token, a few sites, each of enormous value to the United States, can be ringed by exceptionally strong defenses comprised of not one or two but perhaps dozens of mini-missiles or more; and this can be done at acceptable cost to the U.S., because only a few such highly valuable sites exist.) All these measures improve our chance of being able to retaliate against a Soviet attack, and therefore make an attack less likely.
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A point defense decreases the vulnerability of our missiles, and is good. An area defense, directly shielding our cities and their populations, would be better. Can inventive genius find still another device to accomplish this task as well? Once again, the answer is that we already have the invention. It is called the laser. Unlike the smart mini-missile, the laser defense is not inexpensive; it is not yet a proven technology; but it has the promise of protecting our cities against destruction.
A laser is like a searchlight; it produces a beam of light. This beam of light, focused on the metal skin of an ICBM, can burn right through it, just as the light of the sun, focused to a narrow spot by a magnifying glass, can burn through a piece of wood or paper. The difference between a laser beam and an ordinary beam of light is that the ordinary beam spreads out as it leaves its source, so that by the time it has traveled several thousand miles—for example, from the United States to the Soviet Union—the beam is dispersed over an area several miles in diameter. As a result, the intensity of light in any one part of the beam is too weak to hurt anything.
A laser beam on the other hand, has the remarkable property that all parts of the beam travel in the same direction, so that the beam doesn’t spread apart as it travels through space. (Even in a laser beam, the light waves spill out over the edge of the beam to a limited degree and blur it somewhat, but the spreading effect is quite small. In the laser beams being designed for use against Soviet rockets, the spreading effect will be no more than a few feet over a distance of a thousand miles.) If the energy in the laser beam is intense enough at its source to burn through the metal skin of a Soviet ICBM, it will still be that intense, and still able to burn through metal, after it has traveled thousands of miles.
Laser beams have the advantage that they travel at the speed of light, which is 670 million miles an hour, and can cross a continent in a hundredth of a second. Compared to the speed of la
ser beams, even an ICBM is slow, and the laser beam has no difficulty in catching up to one and intercepting it. One of the disadvantages of a laser beam is that, being a beam of light, it is blocked by clouds and haze. For that reason, laser guns work best if placed in a space station or satellite, far above the atmosphere. But putting a laser gun in a space station means that a large amount of equipment and fuel for the laser must be ferried into orbit at great cost. Another disadvantage is that the laser beam must track the moving ICBM with great precision, equivalent to hitting a dime at a distance of 100 miles, so that the beam will stay on the target long enough to melt it.
Because of these and other difficulties, a team of MIT scientists led by Kosta Tsipis concluded a few years ago that “lasers have little or no chance of succeeding as practical, cost-effective weapons.” When President Reagan announced that he was proposing to set the country on this course anyway, Professor Tsipis denounced the President’s plan as “a cruel hoax.” Many other prominent scientists also jumped on the President for his suggestion.
But scientists do not have a very good track record when it comes to making predictions about the feasibility of bold new ideas. In fact, they seem to have a talent for rejecting proposals that later turn out to be of great practical value. Examples abound. In 1903, just before the first flight of the Wright brothers, an American astronomer named Simon Newcomb announced that the laws of physics proved man could never fly. A little later, after airplanes were flying, another American astronomer ridiculed the notion that some day there might be “giant flying machines speeding across the Atlantic… and carrying innumerable passengers.” In 1926, A. W. Bickerton, a British scientist, said that it was scientifically impossible to send a rocket to the moon. Just before the Soviet Union put the first Sputnik into orbit, the Astronomer Royal of Great Britain announced that the idea of launching artificial satellites into space was “utter bilge.” In the weapons field, Admiral Leahy—not a scientist, but a qualified technician—said to President Truman, just before the first successful test of an atom bomb, “That bomb will never go off, and I speak as an expert on explosives.” And Vannevar Bush, who directed the government’s science effort during World War II, offered the following wisdom after the war:
There Will Be War Volume IV Page 25