Prize Essay, 1949
*The opinions or assertions in this article are the private ones of the author, and are not to be construed as official or reflecting the views of the Navy Department or the naval service at large.
A belief that is fast becoming the central core of our national defense thinking X A. appears consistently in many of our national forums; namely, that the atom bomb is a miraculous panacea for all of our military ills. For example, a recent article, based on an interview with General George C. Kenney, then head of the Strategic Air Command, states that “ . . . today, strategic bombing authorities are concerned with only one bomb load—the atom bomb.” However great and awe-inspiring the power of the A-bomb, it is but simple common sense to attempt an evaluation before we accept it as the main shot in our weapons locker. This is particularly important in view of the above- expressed tendency to rely completely and solely on this weapon to preserve our national security. Are we jeopardizing the safety of our nation by such complete reliance?
No one can dispute the fact that the five publicized explosions of atomic bombs have demonstrated almost unbelievable power. Observations and reports from the first experimental blast in New Mexico, the wartime bombings of Hiroshima and Nagasaki, and the two test explosions at Bikini indicate decisively that mankind has found the key to unleash tremendous force for destructive purposes. The United States Strategic Bombing Survey has estimated that to produce results similar to the Nagasaki attack approximately 2,200 tons of conventional high explosives and incendiaries for physical damage plus 500 tons of fragmentation bombs for casualties, a total of 270 B-29 loads of 10 tons each, would be required. The sub-surface explosion at Bikini on July 25, 1946, was reported to have been at least as destructive as 20,000 tons of TNT. When a force of such potentialities has been revealed as a part of our arsenal, it is certainly not amiss to investigate its effects on both the enemy and ourselves, and the military and political considerations which may govern its employment.
EFFECT ON ENEMY
There are but two examples of the use of the atomic bomb in actual warfare—the destruction of Hiroshima and Nagasaki. A review of the results of these two attacks can provide us with an understanding of the effect of the atomic bomb when used against urban targets. In addition, certain lessons may be inferred from the meager reports which have been published concerning the effectiveness of the A-bomb during the Crossroads operation. From these experiences we may make a general assessment of the capabilities and limitations of the bomb insofar as it affects the target.
The Hiroshima attack on the morning of August 6, 1945, caught the Japanese almost completely by surprise; in fact, the explosion came 45 minutes after the “all clear” had been sounded from a previous alarm. The complacency of the Japanese population can be easily understood. Hiroshima had never been attacked in force, but the people were accustomed to seeing stray American planes flying around the city. The U. S. Army Air Force had been using Lake Biwa to the northeast of Hiroshima as a rendezvous point for bombers which had assaulted the larger Japanese cities. Therefore, little notice was paid by the Japanese to the small group of three planes which approached Hiroshima on that fateful morning. Only one bomber, the Enola Gay, carried a bomb; the other two contained observers and their instruments. Because of this indifference and the lack of adequate warning, most people had not taken shelter.
The bomb burst slightly northwest of the center of the city. The nature of the terrain at Hiroshima was such that the blast and ensuing fire levelled nearly five square miles of the city. The exact number of casualties will probably never be determined. Seventy to eighty thousand people were killed, or missing and presumed dead, and an equal number were injured. The casualties at Nagasaki were somewhat smaller—about 35,000 killed and a similar number injured.
Nagasaki was scarcely more prepared for an atomic bomb attack than Hiroshima, although three days had elapsed since the first drop. Once again the appearance of the small raiding group of only two planes caused little concern. The newspapers had made only vague references to the Hiroshima disaster. The devastation caused by the explosion was as horrible and complete as at Hiroshima. However, due to the uneven terrain and the absence of a “fire storm,” less than two square miles of the city were destroyed. (The Japanese city of Kokura was designated the target for the second atom bomb. However, the raiding force found the primary target weathered in, and thus Nagasaki, the alternate objective, became the hapless victim.) Nevertheless the destruction far exceeded that which any conventional bomb would have achieved. What are the miraculous qualities of the atomic bomb to enable it to inflict such tremendous damage?
The bomb is nothing supernatural or incomprehensible. As do ordinary high explosives, atomic bombs release energy, though on an unprecedented scale. The energy takes three forms—heat, blast or pressure, and radiation. Heat and blast effects are evident in ordinary TNT explosions; the radiation effect is unique to the atomic bomb. The energy released in atomic explosion is of such magnitude and from such a concentrated source that its physical properties are of much greater intensity than in the case of an ordinary bomb. This is because the energy produced in an atomic explosion results from the splitting of an atom of uranium or plutonium into two major fragments, a process called “fission,” whereas an ordinary explosion is accompanied only by the rearrangement of the atoms of the explosive material. An illustration of this rearrangement may be found in the simple chemical process of burning. For example, the carbon in coal is combined with the oxygen of the air to form carbon monoxide or carbon dioxide, liberating heat and light in the form of fire. The end products—carbon monoxide or carbon dioxide—still contain the original carbon and oxygen atoms. In an atomic explosion, however, there is a transmutation of the fissionable material. In the fission of uranium (U-235), typical end products are barium and krypton, two entirely different elements. These residual particles have masses whose sum is less than the mass of the original material. This reduction in mass results in an enormous release of energy. In theory, the matter is converted into energy at the rate of 11 billion kilowatt- hours per pound change of mass.
The magnitude of this potential energy supply can best be appreciated if we consider that the entire production of electrical power in the United States in 1946 amounted to 223 billion kilowatt-hours, the equivalent of the energy contained in about 20 pounds of matter. However, in practice there are severe limitations on the amount of energy which can be released in an atomic explosion. Actually only a very small percentage of the matter is capable of being converted into energy. The reduction in mass accompanying the fission of uranium or plutonium varies somewhat according to what are the final products, but has an average of about 1/10 of one per cent. This represents the optimum energy release. Apparently the energy of the bombs used against Japan was actually less than this because the reaction was not complete. Fission in the Japanese bombs was only a small percentage of the theoretical potential. In spite of its fractional efficiency in terms of the theoretical potential, the atomic bomb far overshadows all previous explosives, as demonstrated by the physical results.
As previously mentioned, energy release in an atomic explosion is manifested by heat, blast or pressure, and radiation. The heat energy alone was estimated by Japanese physicists at the astronomical figure of 10- to-the-thirteenth power calories. A fire ball several hundred feet in diameter is formed and the temperature at its core runs into millions of degrees Centrigade. At its edge the temperature has been estimated to be from 3,000 to 9,000 degrees Centigrade. The fire ball is in effect a small sun, and the heat and light which radiate from it can cause charring, start fires, and kill people. At Hiroshima and Nagasaki charred telephone poles were found as far as 13,000 feet from “ground zero,” the point directly beneath the center of the explosion. Mica, with a melting point of 900 degrees, fused on gravestones a thousand feet from the center of the blast. Victims were charred beyond recognition in the immediate vicinity of ground zero. These effects are vastly more intense than any which could be experienced from an ordinary bomb. The blast or pressure results are also magnified.
Pressure at the center rises to tens of millions of atmospheres. At ground zero its force was estimated by the Japanese at from 5.3 to 8 tons per square yard. The blast effects, with their resemblance to the aftermath of a hurricane, were most striking at Nagasaki. Concrete buildings had their sides facing the blast stove in like boxes. Long lines of steel-framed factory sheds, over a mile from ground zero, leaned their skeletons away from the explosion. That the blast effect is tremendous can be readily comprehended from the many pictures of the devastated cities that have been published, and from the damaged wrecks of the Bikini tests. It is much more destructive than the blast from an ordinary bomb. In regard to the third form of energy release, radiation, the atomic bomb is vastly more effective than the usual explosive.
In addition to the emission of heat and light radiation which is common to the ordinary bomb, the atomic explosion also produces dangerous radiations in the form of high-speed neutrons and gamma rays. Gamma rays, like x-rays, can be deadly. Neutrons also have a degenerative effect on the body cells that can be lethal. The high concentration of radioactive emissions at both Hiroshima and Nagasaki caused heavy personnel casualties, even though their duration was very short. The rays proved deadly for an average radius of 3,000 feet from ground zero, and mild effects were observed on people who had been almost two miles away from the blast. An odd characteristic of radiation disease is its delayed effect. People who had survived the explosion itself succumbed to the effect of the radiation over-dose several days after the attack, in some cases two or three weeks later. Japanese casualties from the air bursts were limited to those who had been exposed
to the direct radiation from the bomb. People in the underground shelters were largely protected, but the thin walls of buildings proved no barrier to the invisible rays. At Hiroshima and Nagasaki the radioactive by-products of the explosion and the induced radioactivity in other substances (water, earth, machinery, building debris, etc.) were of little consequence. This was not true in the second Bikini test, however. The explosion of the atomic bomb under the surface of the lagoon produced intense radioactivity in the water. It is estimated to have been the equivalent of many hundreds of tons of radium. A column of this radioactive water a mile high and nearly a half mile in diameter rose into the air and then engulfed about half of the target array. These contaminated ships became radioactive stoves, and would have burned all living things aboard them with an invisible and painless but deadly radiation. The implications of possible wartime applications of such methods of radioactive contamination are awe-inspiring.
EFFECT ON US
A tremendous economic and industrial effort is involved in the development and manufacture of atomic bombs and related atomic weapons. Great quantities of raw materials in the form of pitchblende and carnotite ores are required from which the fissionable U-235 or plutonium may be derived. Huge industrial plants containing hundreds of thousands of delicate and precision-made instruments and other equipment are necessary. Great numbers of men, from laborers to highly skilled and trained scientists and top-flight engineers and technicians, must be available. In certain of the processes huge amounts of power are required, and in others an abundant supply of cooling water is a necessity. All of these factors have potential limitations, especially when they may conflict with other possible wartime demands.
The quantity of fissionable material which can be made available is subject to limitation. So far, only U-235 and plutonium have been used in the manufacture of atomic bombs. Both of them are derived from uranium present in raw uranium ores. Uranium is a fairly plentiful material—about four parts in a million in the earth’s crust, more plentiful than gold, for example. But only two ores, pitchblende and carnotite, are of value as a source of the uranium metal with the present methods of extraction. Usable deposits of these ores are rather limited. Uranium metal, a combination of U-235 and U-238, represents only a small fraction of the ore. U-235, the part of the uranium metal which can be used as the fissionable material in the manufacture of atomic explosive, is in turn present in very minute proportion. Seven-tenths of one per cent of the uranium metal is U-235. The remaining U-238 can be processed in an atomic pile to form plutonium, another source of fissionable material.
The separation of U-235 from the uranium metal extracted from pitch-blende or carnotite could not be accomplished by chemical methods. Instead, other processes had to be developed to capitalize on the infinitesimal weight difference between the lighter U-235 and the heavier U-238. Four methods were finally devised—gaseous diffusion, thermal diffusion, centrifugal, and electro-magnetic. All of these methods called for the mass production of precision instruments and equipment, some more delicate than any that had ever been manufactured for laboratory work. In the gaseous diffusion process, for example, thousands of containers about the size of a depth charge case were needed. Yet the gas, uranium hexafluoride, was so fiercely corrosive that ordinary metals were unsatisfactory. Only nickel was found to be acceptable, but the first increment of these tanks would have required all of the nickel mined in America for two years! The problem was finally solved by electroplating nickel on steel to standards of perfection that were undreamed of in the commercial world. New techniques in cutting and welding glass piping were developed; huge numbers of high speed pumps of new design were made. Unbelievable standards of operation were achieved. For example, although a vacuum of one inch is very good in power plant practice, the gaseous diffusion plant maintained a vacuum twenty-five million times greater!
Tremendous amounts of power are required to operate the plants at Oak Ridge, Tennessee. Though they were located in the Clinch River Valley in order to tap the TVA supply, one of the world’s largest steam power plants was also erected there. In the manufacture of plutonium a plentiful supply of cooling water was necessary. For this reason, the Hanford Engineer Works was built near the Columbia River in the State of Washington. With three atomic piles in operation in 1945, the liberated atomic heat had raised the temperature of the river fractionally, even though the water underwent a long decontamination period before flowing back into the river.
As can be readily seen, the development and manufacture of atomic weapons imposes a huge burden on our economy. The capital outlay for the construction of the plants alone is staggering. The original cost of the Hanford Works was $350,000,000. The gas diffusion plant at Oak Ridge, only a part of the establishment at that location, consisted of 63 buildings costing half a billion dollars. It was the world’s greatest continuous chemico-physical process factory. The principal building was a windowless U- shaped structure, 4 stories high, 2,500 feet long, and 400 feet wide.
The adoption of a policy which places sole reliance upon the atom bomb would have severe effects on the pace of military progress, in that it would bring about a stagnation in the development of other weapons and techniques. Having committed ourselves to the use of one weapon and one method of delivery, we would find no incentive to invent new and different means of employing military force. In a world in which scientific achievement can tip the balance in time of war, we would be channeling all of our effort toward one limited objective—progress in atomic explosives to be used solely with long-range bombers.
Our own history provides an example of the damaging effect of sole reliance on an imperfect weapons system. After the Barbary Wars, Congress adopted a “gunboat policy” which called for the construction of large numbers of small non-seagoing coastal gunboats, to the exclusion of sea-going vessels. It was reasoned that such a force would deter an attack from overseas and yet would not permit our involvement in conflicts in foreign waters. In the later War of 1812, however, larger enemy frigates and sloops had no difficulty in deeply penetrating our territorial waters. Washington itself was burned by the British. Our internal commerce, dependent upon coastwise seaborne trade, was paralyzed; foreign trade virtually ceased to exist. The resultant depression was one of the worst in our history. Our fleet of 176 gunboats was useless. Our few naval victories were the result of individual frigate and sloop actions in distant waters. A few American ships-of-the-line, in place of the numerous small gunboats, and at no greater cost, could have stopped much of this, besides affording a reasonable measure of protection to our ocean-going coastwise commerce, and even some support to our foreign trade. The gunboat policy was a blunder both from the naval viewpoint and that of national economics. From a purely military point of view, the stagnation brought about by exclusive reliance in a faulty weapons system can lead to fatal weaknesses in other lines which would cause our downfall. This is particularly true when we consider that the effectiveness of an atomic assault is dependent upon our means of delivery.
We face the danger of complete impotency if an enemy is able to develop countermeasures against our delivery agent. In other words, if we confirm as our policy the sole reliance upon one weapon—the atom bomb delivered by aircraft—an aggressor must merely devise a way to counteract either the bomb or the plane in order to render us powerless. At present, the development of a counter-agent to the bomb itself seems unlikely. Likewise, under present conditions, aircraft appear to have the upper hand over the means of defense. Such superiority is not guaranteed, however, for the indefinite future.
There are also several other military considerations which limit the use of atom bombs. Undoubtedly it restricts the variety and flexibility of offense, both from a strategical and tactical viewpoint. Strategically, sole reliance on an air-atomic policy would not only eliminate the possibility of employing the many other forms of military power but also would exclude the varied use of economic, psychological, intellectual, political, and moral forces. Tactically, it is the same as issuing an arbitrary ruling to field commanders that nothing but flame-throwers shall be used in any and all tactical situations and against any and all targets.
We must also note that the use of atomic bombs can, under some conditions of employment, so pollute and contaminate the objective area that the devastated region is denied to us as well as the enemy.
Finally, it should be remembered that the atom bomb is not economical for use against pinpoint targets. Would we employ the atom bomb, capable of demolishing an entire city, to destroy an isolated railroad bridge? Certainly not, when we recall that the bombs may be limited in number and that each one represents a large investment in dollars alone.
Thus, in deliberating whether to adopt an exclusive policy of absolute dependence on the atom bomb, we must realize that from a purely military standpoint such a course can lead to stagnation of progress in other weapons systems, will create the danger of impotency due to countermeasures against the delivery agent, will seriously limit the diversity of offensive means, can contaminate an objective to our disadvantage, and will demand uneconomical usage against certain targets. Employment of the atom bomb is also subject to political considerations.
In discussing some of the political factors which influence the employment of atomic bombs, we must bear in mind that military policy is a means to an end. Military policy is an adjunct and corollary to national policy, and is governed directly by our broader national aims. Therefore a policy of sole dependence on atomic weapons must be compatible with the larger policy.
It is a matter of public record that the United States has encouraged and continues to support the world-wide adoption of measures which will bring about effective international control of atomic energy. An integral part of any system of international control would be an international authority to prevent the manufacture and use of atomic bombs for war purposes. A treaty covering this subject would guarantee the right of free and full international inspection and would provide for deterrents against offenses and punishment of offenders, without the privilege of a veto to protect willful violators or to hamper the operations of the international authority. Even though the first attempts to establish such an authority have met with failure, we have not officially abandoned or reversed our policy. If, in the face of this, we adopt a military policy of absolute reliance on the atom bomb, we are either incredibly stupid or blatantly hypocritical. Presuming that we are sincere in our desire to establish international control of atomic energy, a clever potential enemy could cause our complete disarmament by the simple expedient of agreeing to outlaw atomic weapons and institute a system of international inspection. On the other hand, if we are not prepared to accept complete disarmament under these circumstances, we cannot honestly continue to support our previously announced national policy. The choice of a military policy of sole dependence on atomic bombs would be interpreted by most people as a de facto repudiation of our position on international control.
Politically speaking, it would not be necessary to outlaw the use of atomic bombs by treaty to reduce us to impotency. There are many instances in which the employment of atomic weapons would be entirely practicable from a military point of view but would be impossible from a political standpoint. For example, could we justify the use of atomic weapons in a “luke-warm” war?
If in the ideological struggle between communism and democracy, internal communistic elements should overthrow the established constitutional government of a friendly nation, could we use atomic bombs in support of the democratic forces? Could we drop a bomb in Italy, or France, or Latin America, if the local communists usurped control of the government? Obviously, no. Nor could we retaliate against the tide of communism by dropping an atom bomb on the original source of communistic strength.
Even if a “hot” war should break out, we would find occasions when we couldn’t employ atomic bombs. It would not be politically or morally feasible to use the A-weapons in over-run countries. Could we have blasted Brest or Manila into atomic dust in the last war, merely because enemy forces were using those ports as bases for operations against us? Are we to murder hundreds of thousands of former allies or friends just because a few of the enemy are in their midst?
Aside from the moral implications of the adoption of a military strategy which places exclusive reliance on the atom bomb, there are several other practical considerations. Most observers agree that a psychological campaign to wean the enemy population from their leaders would be of marked consequence in a future conflict. Some go so far as to say that the split already exists, and that the exploitation of this fissure would play an important part in achieving victory. Yet, by relying solely on the atomic weapons, we sacrifice this psychological advantage. An announced policy of mass population extermination would insure the unity and last- ditch struggle of an aggressor nation, would weld together the people and their leaders under the barbaric threat of wholesale genocide.
From a purely material point of view, an exclusive air-atomic military policy would have severe repercussions. Atom bombs cannot be made in the small, handy pocket size. Due to the inherent characteristics of atomic fission, the bomb cannot be reduced below a certain critical magnitude. Hence there is also a definite irreducible minimum to its explosive power. It is quite probable that the bomb cannot be made much smaller or less powerful than the Hiroshima or Nagasaki type. Therefore each time an A-bomb is dropped, a large area will be laid waste, including without doubt a considerable number of non-military targets. At Hiroshima, out of a total of 90,000 buildings in the urban area, 62,000 were totally destroyed and another 6,000 severely damaged. Most of these were residential structures, or other non-military targets such as hospitals, schools, stores, etc. This poses the tremendous problem of postwar rehabilitation and reconstruction.
Thus, when considered in connection with our broad national aims, such a policy of absolute dependence is in marked dissonance. It would call for abandonment of our announced position on international control of atomic energy, would deprive us of the conventional instruments of military force for use in a lukewarm war, would leave us powerless to wage war against an aggressor in occupied areas or over-run countries, would make untenable our present strong moral position as the champion of freedom and democracy, would condemn to failure a psychological campaign to exploit a rift between an enemy population and their leaders, and would cancel out the anticipated fruits of victory through the overburdening weight of wide-scale postwar relief and reconstruction.
In this discussion we have reviewed briefly the broad capabilities and limitations of the atomic bomb. We have examined the effects of its employment, both on the recipient and on the deliverer, and have analyzed the major military and political considerations which govern its use. From this scrutiny we must conclude that the adoption of a military policy of exclusive reliance on the atom bomb would jeopardize the security of our nation. The strategy of victory through the sole agent of mass atomic destruction is not only morally untenable, but has dubious chances of success politically and militarily.
However, since the threat of atomic warfare still hangs over us, we cannot cease to maintain our atomic advantage, if only for insurance. Under these circumstances, a sound program for national security would include atomic weapons as well as the conventional forms of military strength. On the other hand, it must be remembered that military force is only a segment of our national power. Military policy must be the servant and not the master of national policy; military might must be used in harmony with the economic, intellectual, psychological, political, and moral factors which also form a part of our national strength. We must keep the atom bomb in our arsenal of weapons, but we must also be prepared to fight a war without it. We must realize fully what an atom bomb cannot do as well as what it can do.
A graduate of the Naval Academy in 1940, Lieutenant Commander Seim served in South American, West Indian, and Pacific waters before World War II. He was assistant gunnery officer of the U.S.S. Independence when she was torpedoed in the Tarawa campaign, and subsequently was gunnery officer on the staff of Commander Carrier Division 4 and 5 in Task Force 38. After Japan’s surrender he served in the Western Pacific, Philippines, China, and Japan, and is now on duty in the Office of the Chief of Naval Operations, Navy Department, Washington, D. C.