The practices of the 17th, 18th and 19th centuries gave rise to certain generally accepted principles governing naval warfare. Various attempts to codify these principles in convention form, however, were generally unsuccessful. While it is true that there was in existence at the outbreak of World War I the Declaration of Paris of 1856, the various Hague Conventions of 1907, and the unratified Declaration of London of 1909, none of these dealt specifically with the problems which were to be generated with the advent of the submarine as an important weapon of warfare.
The generally accepted customary rules with respect to destruction of enemy merchantmen at sea were based on the unquestioned superiority in power of the surface warship over the merchantman and on the proposition that the merchantman was basically a noncombatant. As a noncombatant she was immune from attack by an enemy warship unless by her actions she took an active part in hostilities or unless after having been duly signalled to stand by for visit and search, she either refused to do so or actively resisted the warship’s actions. The traditional rules provided a liability of the enemy merchantman to seizure and condemnation in the prize courts of the captor, rather than a liability to direct attack.
Destruction of an enemy merchantman was considered permissible only in certain exceptional circumstances—where the sending of the captured ship into port for condemnation was either impossible, highly inconvenient, or would endanger the capturing ship—and in these circumstances the captor was under an obligation to place the ship’s crew, passengers, and papers in a “place of safety” prior to the destruction. There was no duty on the part of the merchantman to submit peaceably to the seizure, and the merchant vessel was free to take any action possible to avoid it. This could consist of a persistent refusal to lie to, active flight, or even the use of force against the enemy warship, and merchant vessels were permitted to carry defensive armament for this latter purpose. Should any of these actions be taken, however, the rule providing for immunity from attack, and that prohibiting destruction without first placing passengers, crew, and papers in a place of safety no longer applied.
These rules were generally accepted by nations prior to the advent of World War I, but the circumstances of that conflict soon demonstrated their inadequacy to serve in any measurable degree to regulate the activities of the submarine. In previous wars the commerce destroyer had been a heavily armed surface ship which was not seriously endangered by closely approaching a merchant ship—even an armed one—in order to compel her to submit to visit, search, and possible seizure. Now the principal weapon for commerce destruction became the submarine which did not possess these same advantages over the merchantman. The relatively small size of the submarine made it impossible for it to place a prize crew on board the merchant ship, to escort her into port for condemnation in prize, or to take passengers and crew on board before destroying its captive. The submarine depended entirely on the element of surprise to render its commerce destruction operations effective, and strict adherence to the traditional rules would have precluded its effective use for this purpose.
The existing rules were heavily weighed in favor of the belligerent which was prepared to fight a traditional type of warfare at sea— where surface warships were the principal weapon for combat. Little, if any, consideration was given to the belligerent who was incapable of fighting this kind of war, but who was prepared to fight a new kind of sea warfare with the submarine.
World War I was not long in progress before it was apparent that the new mode of warfare could not be reconciled with the existing legal framework. Although none of the belligerents claimed at any time that they were not bound by the rules of naval warfare, all were able, when their interests required, either to interpret the law to permit their particular activities, or to make use of the doctrine of reprisals to justify their actions. Thus, on 31 January 1917, the German government announced its policy of unrestricted submarine warfare, which meant sinking merchant ships without warning, with no attempt to safeguard the lives of the crews of the merchantmen or their passengers. Thus it was that the rules which had taken several hundred years of careful development failed to meet the test of effectiveness when faced with a powerful new weapon in the hands of a belligerent who felt that its survival as a nation depended on the defeat of its enemy and that this new weapon was its hope of victory.
The United States, Great Britain, France, Italy, and Japan met in Washington in 1921 to attempt to reach an agreement on comparative naval strength. Although it was urged at this conference that the submarine be outlawed as a weapon of war, it was decided, instead, to provide a legal framework for the control of submarine operations. The result was Treaty II of the Washington Conference of 1922 which restated the customary rules of surface ship action against merchantmen, made them applicable to the submarine, and provided that violators “shall be deemed to have violated the laws of war and shall be liable to trial and punishment as if for an act of piracy.”
This Treaty failed to secure ratification, however, and this led these same signatories to meet in London in 1930. Some of the more objectionable portions of the 1922 Washington agreement were deleted, and the London
Naval Treaty of 1930 was announced. The pertinent parts of this agreement are contained in Article 22 and read as follows:
“22. The following are accepted as established rules of International Law:
(1) In their action with regard to merchant ships, submarines must conform to the rules of International Law to which surface vessels are subject.
(2) In particular, except in cases of persistent refusal to stop on being duly summoned, or of active resistance to visit and search, a warship, whether surface vessel or submarine, may not sink or render incapable of navigation a merchant vessel without having first placed passengers, crew, and ship’s papers in a place of safety. For this purpose the ship’s boats are not regarded as a place of safety unless the safety of the passengers and crew is assured, in the existing sea, and weather conditions, by the proximity of land, or the presence of another vessel which is in a position to take them on board.”
These provisions were reaffirmed verbatim in the London Protocol of 1936, and thereafter were acceded to by 48 states. All of the naval powers, including Germany, were bound by these rules at the outset of World War II.
In spite of the lessons, therefore, which should have been manifest, and in spite of the continued development of the submarine as a weapon designed principally for commerce destruction, the legal framework to regulate its participation in conflict remained the same in 1939 as it had been in 1914. The only contribution which was made during the interval between the two great wars was a codification of the old, traditional, 19th century rules-' rules which had been developed without the experience of unrestricted submarine warfare, and rules which had proved inadequate to regulate this new form of sea warfare.
There is no need to recite the practices of the various belligerents during World War II. It is sufficient to observe that Germany from almost the outset of the war adopted what amounted to unrestricted submarine warfare. Similarly, although possessing preponderant surface strength, Great Britain did likewise in the latter stages of the war. In the War in the Pacific, the Japanese sank a U. S. merchant vessel in violation of the London Protocol within hours after their attack on Pearl Harbor, and the United States immediately ordered and executed “unrestricted air and submarine warfare” against Japan.
Whatever may be said concerning the validity of the legal framework for warfare at sea at the beginning of World War II, and however eloquent the arguments may be in justification of the activities of the submarines of all belligerents during that conflict—either as the operation of legitimate reprisals, or because of the changed character of the merchantman as an armed and active part of a belligerent’s war effort at sea—there is no denying the fact that this conflict saw widespread violations by all belligerents of the traditional law as codified in the London Protocol of 1936.
It seems obvious, therefore, that the pre- World War II treaty structure, which reflects rules which have twice within this century been incapable of regulating the submarine as a commerce destroyer, can no longer be regarded as “law” if we mean by “law” a rule to which we can reasonably expect general adherence.
The principal difficulty today confronting those who would frame laws of warfare, and specifically within that context, laws of submarine warfare is that modern warfare is considered to be the total war experienced during World War I and World War II. This subsumes a compelling emphasis on economic warfare with, as one writer put it, “ . . . the annihilation of enemy maritime commerce as a major naval objective.”
But if we should seek to frame rules with “total” war—long, protracted, and characterized by a war aim of total subjugation of the enemy—as a sole basis, we would be making a mistake similar to that made by the treaty makers of the 1930s. Their efforts were directed toward regulating one type of conflict— a limited type wherein the objectives of belligerents would be confined and would not reach total proportions. We must not now go to the other end of the scale and formulate rules to regulate “total war”—and that situation only. If we have learned anything from past history, surely it is that a set of rules so limited in their application will not suffice.
It is totally unrealistic now, just as it was in the 1930s, to attempt to formulate one set of rules which will be applicable in all circumstances. If we are to regulate conflict successfully, we must establish norms to which all can agree and to which we can expect general adherence. We must be able to operate within a system which will recognize the differing natures and varying degrees of conflict, the respective aims of the participants, the varying natures of their power bases and the technology available to each of them.* And most important, we must weigh these factors in terms consistent with the basic principle of conflict—an economy in the application of force.
Using such a system, it is not inconceivable that we will arrive at an acceptable rule of conduct which would be appropriate and applicable in one situation but which would be distinctly inappropriate and inapplicable in another. In a total conflict where the objectives of the belligerents are politically unlimited, and where the technology of violence available to both is of the most advanced nature, realistic community expectation of a standard for mutual compliance may be one thing, while in a conflict between these same participants, where mutual limitations on political objectives have been imposed, a realistic standard for compliance may be totally different.
The two basic and operative principles of the laws of war which must circumscribe any inquiry into the rules of warfare are the principle of military necessity and the principle of humanitarianism. Since the days of Grotius, attempts to humanize warfare have constantly brought these two principles into conflict. As a consequence, the literature abounds with discussions concerning the meaning of the terms, and especially with treatises on the meaning of the term “military necessity.” For our purposes, we may use the definition of the terms found in the Laws of Naval Warfare, an official U. S. Navy publication, as follows:
“Military necessity. The principle of military necessity permits a belligerent to apply only that degree and kind of regulated force not otherwise prohibited by the laws of war, required for the partial or complete submission of the enemy with the least possible expenditure of time, life, and physical resources.
“Humanity. The principle of humanity prohibits the employment of any kind of degree of force not necessary for the purpose of the war, i.e., for the partial or complete submission of the enemy with the least possible expenditure of time, life, and physical resources.”
These terms are defined here in their broadest conception, and the difficulty of their application to specific factual situations is obvious. It is observed, however, that they combine to set forth the basic principle of economy in the application of force which Professor Myres McDougal describes as authorizing “such destruction and only such destruction, as is necessary, relevant, and proportionate to the prompt realization of legitimate military objectives.”
Used in this definitional context the terms have come to be understood as expressing the general confines within which violence may be lawfully exercised once conflict has erupted, and the conventions announcing rules of warfare which have been entered into during the past 100 years have generally had as their purpose the balancing of these two concepts. The specific rules announced in conventional form have sought to set forth a balance, to which in a factual context of war, national decision-makers would be willing to adhere and to which they could reasonably expect adherence by their enemy counterparts. Similarly, the usages and practices which have given rise to customary rules have been based on this same philosophy.
The essential thrust of all these rules has traditionally been the reservation to a belligerent, within the bounds of humanitarian- ism, the right to attack, at sea, those objects which were recognized as legitimate military objectives. Hence, it has always been recognized that attack without warning on an enemy warship was lawful. The merchant ship, however, enjoyed a different status. Although it was recognized that enemy commerce at sea was a legitimate military objective, and hence subject to appropriation by the enemy, the Powers were willing to permit a balance of the principles of military necessity and humanity so as to provide essentially a noncombatant status to the merchant ship. The effect of this was to make the merchant ship immune from direct attack without warning, except in certain exceptional circumstances, and to provide safeguards for the protection of the noncombatants aboard the merchant ship in situations where it was necessary to sink her. The doctrine of an economy in the application of force was thus given practical effect by the rule makers—in both customary and conventional form—and it continued to be as long as the force permitted by these specific rules was sufficient to accomplish the objective.
The circumstances of World War I and World War II, however, effected a dramatic change. No longer were the traditional visit, search, and condemnation in prize procedures adequate. Military necessity demanded something more—a new balancing was required. In the cold light of reality, all belligerents made this balance weighing heavily—almost completely—on the principle of military necessity. And the judicial pronouncements after the hostilities were concluded gave practical recognition to these decisions by refusing to convict the individual responsible for the German decision of any violation with respect to enemy merchantmen and by refusing to impose punishment for his technical violations with respect to neutral merchant shipping. This latter decision has been justified by some as merely a mitigation of punishment because of the circumstances; but when reduced to its essence, it means nothing less than that when all of the factors of the conflict were considered together, the balance—or imbalance —which was achieved did not offend the essential principle of warfare—an economy in the application of force in attaining a legitimate military objective.
Any system for the effective regulation of future conflict must have as its sine qua non the principle of an economy in the application of force and it must be sufficiently flexible so as to be applicable in varying situations. It is considered foolhardy to attempt to set forth one set of inflexible rules which would govern hostilities of varying intensities, with participants of varying and differing power bases, who contend for objectives of varying importance, and who have available material, technical, and human resources of varying magnitudes. If we are to have a law of war —and specifically within this context, a law of sea warfare—the framework must provide norms to which a national decisionmaker, faced with a particular fact situation with its infinite variables, can reasonably be expected to adhere. Any system which does not provide for a consideration of all the variables which are presented to the decisionmaker will not provide for this expectation of adherence. What we need is not an ironclad system of “rules” within which to cubbyhole our factual situations. Rather, we need guidelines which will assist a decision-maker in discerning the particular standard of conduct, in the particular fact situation which he faces, to which the general world community expects him to adhere.
The first and most obvious consideration in determining a norm of expected compliance is the alignment of participants in the conflict, their respective power bases, their geographical proximity to each other and to the scene of land combat, and their dependence on the lanes of maritime commerce to sustain their war effort.
In the case of a belligerent whose power base is essentially land oriented, as was Germany in both World Wars, and as would be the Soviet Union and Communist China in a conflict fought in Continental Europe or on the land mass of Asia, it is obvious that dependence on the sea lanes to sustain their effort is minimal. The converse is true, however, of a basically island power, such as Great Britain or Japan, or of a power far removed from the scene of land hostilities such as the United States in World Wars I and II, in Korea, and in the current effort in Vietnam.
The essential point, here, is that as differences in the power base orientation of the respective belligerents concerning the particular conflict being fought become greater, it becomes more likely that the land oriented power will strike at that aspect of his adversary’s war effort which tends to narrow that differential and which is most exposed to attack. As decision in this context becomes necessary, the decision-maker must consider a multitude of other factors.
Among the most important factors in the decision process will be the political objectives for which the decision-maker wages war. This highlights the importance of the theory of war as a means through which political objectives are sought. Clausewitz discusses this in the following language:
. . . war is only a part of political intercourse, therefore by no means an independent thing in itself. We know, of course, that war is only caused through the political intercourse of governments and nations; but in general it is supposed that such intercourse is broken off by war, and that a totally different state of things ensues, subject to no laws but its own. We maintain, on the contrary, that war is nothing but a continuation of political intercourse with an admixture of other means. . . .
Implicit within this reasoning is the fact that war is not an irrational or senseless enterprise. It has a definite political purpose which can be satisfied, and the decision-maker will seek to satisfy that purpose with a minimum expenditure of his own values and a minimum destruction of those of his adversary. Again, in Clausewitz’ language:
The smaller the sacrifice we demand from our adversary, the slighter we may expect his efforts to be to refuse it to us. The slighter, however, his effort, the smaller need be our own. Furthermore, the less important our political object, the less will be the value we attach to it and the readier we shall be to abandon it. For this reason also our efforts will be the lighter. Thus the political object as the original motive for war will be the standard alike for the aim to be attained by military action and for the efforts required for this purpose.
A decision to wage war, therefore, will have as its purpose the attainment of a definite political objective, and the force to be expended, and that which the decision-maker can expect in return, will be roughly equal to the scope of the objective and the value assigned to it. Insofar as decision-makers can divine the objectives of their adversaries, a rough calculation of the amount of force to be felt, and that necessary to be exercised in return, can be made. The legal implications, here, are apparent. The norm of expected compliance will vary in accord with the political objectives for which the war is fought.
Two historical experiences will serve as illustrations of the operation of this principle. The first was the experience of the two World Wars. As the belligerents came to realize that both conflicts were not to be compromised short of total defeat of the enemy, or stated otherwise, as their political objectives broadened, so also did their conception of legitimate military ends and the extent of force required to attain them. The result was, inter alia, unrestricted submarine warfare against the sea lanes supporting the enemy’s war effort.
On the other end of the scale is the current situation in Vietnam. Although there has been no formal declaration of war in Vietnam, there is nevertheless a conflict of extensive proportions being waged. Significantly, we have, here, one “belligerent” supported principally through land means, and another who is supported entirely through the use of the sea lanes. Why is it that we have not seen attacks on those sea lanes of supply? It may be argued that the “land power” does not have available the force to wage such a sea war, but this overlooks the fact that the source of supply of munitions to wage a land campaign could provide the few submarines it would take to affect seriously the Vietnamese lines of maritime supply. The reason why this is not done, however, is obvious. The political objectives of the belligerents are kept limited for fear that what is now essentially a local conflict will spread to embrace a greater land area and to involve more effort of, and danger to, the powers which support that conflict. Thus, the limitations mutually imposed on political objectives provide a climate where determinations concerning a standard for compliance in submarine warfare are not even required.
Unrestricted submarine warfare has been experienced in the past in only those conflicts which approached total dimensions. We could, however, have a situation where such warfare might be experienced, but only in limited geographic areas. Such could have been the case in the U.N. police action in Korea, and it could be seen in any similar area where one belligerent is primarily dependent on maritime supply. In such a situation the decision-maker must consider not only the military necessity, as he sees it, of broadening his objectives to include this shipping, but also he must consider his ability in terms of methods and technology available to undermine it. Also, of course, he must take into consideration the effect such a broadening will have on the enemy’s hitherto limited objectives and his consequent limitations on the use of methods of coercion. Inextricably entwined, therefore, with any such broadening of hostilities will be the relative technologies available to the respective belligerents and the degree of importance each attaches to the object of attack which the broadened objectives encompass. Hence, a norm for compliance in such broadened hostilities will necessarily be determined in large measure by these factors.
In between the two opposite ends of the spectrum of war, therefore, the decisionmaker must assess the political objectives of his adversary vis-ct-vis his own and the means available to each. Only by doing this, and by a rational application of the basic concept of military necessity, can a norm of expected adherence be found.
The methods of coercion and the war technology available to the initial decisionmaker, to his enemy, and to his potential enemies, are not only important for purely tactical military reasons, but they approach transcendent importance in a determination of an expectancy of over-all costs of the objective for which the war is being fought. Given that war has a definite political objective, then the costs of achieving that objective through this means is a fundamental consideration in the decision-making process. Not only is this true in an initial determination of the purpose of war, but it is also true when decisions are necessary which may lead to a broadening of its scope.
Military technology has produced weapons of such terrifying destructiveness that the possible costs of pursuit of large scale political objectives could be the annihilation of entire nations. Should nations possessing these weapons of mass destruction find themselves locked in a conflict incapable of resolution short of complete subjugation of the enemy, the probability of their use would be great; and an assessment of the costs to the user, in terms of retribution, makes such a prospect unthinkable. This very fact tends to dim the prospects of such a conflict. Modern science and technology has worked a revolution in the means of warfare, and in so doing, it has also worked a revolution in the political process of which war is but a part.
The advent of nuclear weapons has been met with the same series of conferences, argumentations, and negative results that greeted the advent of the submarine as an instrument of warfare in the first quarter of the 20th century. Thus, the nuclear weapon, as is the submarine, is still with us, and the very magnitude of their destructiveness and the inability to legislate against their use, has given rise to a new trend of thinking within which the seeds of rules for future conduct of hostilities may find fertile ground.
Current literature abounds with discussions of the nuclear stalemate, characterized by relative parity in destructive capacity of two great power centers, each possessing the apparent ability to annihilate the other even though it, itself, may suffer a similar fate. Surveying this situation, many feel that the exorbitant costs of such a conflict militate toward a future mutual limitation of political objective, and thus toward a forward strategy of limited, rather than total, war.
In the submarine warfare of the future, although the new technology of the submarine will play an important part in the tactical employment of that weapon, the major effect of technology on this type warfare will undoubtedly be made, not by the submarine itself, but by the overriding significance of the possibility of nuclear warfare. This may very well mean the effective abolition of the submarine as a commerce destroyer in the type war which will be fought in the future. But to premise any norm of expected compliance upon such an assumption would be repeating the mistakes of the 1930s—a relied-upon hopefulness that the world would never again see a conflict in which commerce destruction would become an essential element in a belligerent war strategy.
In determining the legality of future resort to the submarine as a weapon of commerce destruction we must divorce from our thinking the concept that a decision can be based on a single, unalterable rule such as that announced in the London Protocol of 1936. Rather, the decision-maker in his determination to so use this weapon must be guided by a multitude of factors. Among these must be a consideration of the participants in the conflict, their relative power bases and locations with respect to the scene of land hostilities; the objectives for which they fight; the relative degrees of coercion available to each of them; and the general circumstances of the conflict. Every such situation must be assessed as to its lawfulness, both as a matter of initial decision and of later review, on the basis of the specific operational situation, considered in context of all factors mentioned above. The decisions will have to be based on a weighing of the requirements of military necessity and humanitarianism in the context of the particular encounter, and we should expect that as a participant’s war objectives become more important to him the scales will weigh more heavily on the side of military necessity. The legitimacy of a participant’s military objectives, in the general context of the conflict being waged, and the degree of force reasonably considered necessary to attain them, will in large measure determine the lawfulness of particular acts.
This is not a “new” international law for the submarine, for it is a simple restatement of the basic principles of the laws of war in context with the lessons learned from World War I and World War II. But it does give practical effect to lessons which have too long been ignored.
* Such a system has been suggested by Professor Myres McDougal and his associates. The discussion which follows is based in large part on their proposals.