McNair Paper Number 33 Chapter 3, January 1995
The world after 1918 tended to recognize a new jus ad bellum . . . and to distinguish . . . sanctions authorized by the League of Nations from . . . aggression.(Note 1)
The turbulence of World War I was on the ebb, a war that "spelled death to so many millions of men, spread desolation over so much of the Continent of Europe and shocked and imperiled neutral as well as belligerent nations."(Note 2) World states, individually and collectively, attempted at this time to restore the international order and re-establish the force of the legal system. World interdependence had grown; it was evident that war anywhere might affect everyone. The "indivisibility of peace" became an accepted truism.
In this environment the international community undertook legal obligations that seem inconsequential today because, for the most part, they proved ineffective in the face of determined aggression. At the time, however, their intent and ethical underpinnings were unprecedented.
Although the details of these efforts are beyond the scope of this work, it is important to review at least briefly their influence upon the world's view of neutrality's survival from World War I and the rights and duties of neutrals.
The League of Nations emerged as a direct result of the war. Its Covenant(Note 3) was part of the Treaty of Peace. Agreement to the provisions of the Covenant was supposed to be part of legally ending the state of war. It asked too much, but it also promised a great deal:
The era of legally unrestricted right to resort to war, neutral indifference to the aggressive use of force, rival alliances and competitive armaments, and cynical manipulation of power relationships was past. In the new era war anywhere would be everybody's business; discussion at the bar of world public opinion would supersede Machiavellian browbeating tactics; and the security of nations would be a matter of collective responsibility.(Note 4)
The problems with the Covenant involved legal and policy matters perceived as going to the heart of a state's sovereignty. Some argued that Article 10 of the Covenant allowed the League to decide when member-states should go to war, in effect ending neutrality and a state's sovereign right to elect and conduct a neutral policy--at least as neutrality was framed in the Hague Conventions. The well-intentioned but unfortunate wording obligated members of the League to "preserve as against external aggression the territorial integrity and . . . political independence of all Members."(Note 5)
Further, it was not easy to identify who decided, under the Covenant, when aggression occurred, determining which side was the aggressor was an obviously important decision if it bound states to act. Consequently, the threat that Article 10 might require an unwanted and unnecessary war for the United States was one of the reasons the Senate refused its consent to the Treaty of Versailles and its included Covenant.(Note 6)
The interpretation that neutrality essentially had been outlawed ignored the fact that this treaty provision did not claim to bind nonparties. Moreover, even with regard to parties, if they failed to act against external aggression despite the treaty's expectations, they could still choose neutrality. States bordering a war that chose neutrality could claim they contributed something by limiting the scope of the conflict. Certainly, weak states bordering a belligerent would not improve the situation by declaring war and sealing their own imminent defeat.
It seems remarkable, but for a variety of reasons--which were valid at least in part, and certainly proved exceptionally persuasive at the time--the United States stayed out of the League of Nations. President Wilson had crafted the Treaty of Versailles and the Covenant himself, but he was not the last president to find that the Congress of the United States is fully empowered to seek what it sees as the best course for the nation.
While the United States made a policy decision to stand alone, the world continued to evolve into a smaller and even more dangerous place. Industrialism and sea transport were bringing the community of nations closer together. While the United States viewed the oceans as defensive barriers, those same oceans formed its common border with all other maritime states, and thus they also became both the interior lines of communication of the United States and corridors through which the horrors of war could be delivered.
Article 11 of the Covenant made even the threat of war "a matter of concern for the whole League,"(Note 7) but as later experience demonstrated, the Covenant, like the Hague Conventions and the Declaration of London, attempted to set out principles easy to believe in but difficult to apply. It would seem that some states felt they had accepted a commitment to refrain from war even when war might be in their national interest, but possibly to go to war when it was not, according to Professor Claude:
The history of the League was a record of constant efforts to strengthen and to weaken the collective security provisions of the Covenant. This was not so much a contest between friends and enemies of the principle of collective security as a vacillation between the desire to enjoy the benefits and the urge to avoid paying the price of collective security. The League could neither take collective security nor leave it alone.(Note 8)
The League's efforts might reflect an inherent flaw of all collective security arrangements, which are concluded for the purpose of dissuading other states from aggression. When these arrangements fail in their primary purpose of deterrence, too frequently only states directly affected are prepared to attempt to fulfill the arrangement's secondary purpose of re-establishing the status quo ante. Each time a state fails to undertake its responsibility regarding this secondary purpose it weakens the deterrent effect of any future collective security effort. Recent history in the Persian Gulf region proved that collective security can work if strong leadership, effective diplomacy, and a clear identification of the aggressor exist. The response to trouble in the Balkans, however, makes it obvious that consensus can still be elusive.
As for the Covenant's effect on the law of neutrality, however, claims that neutrality was forced into desuetude by the Covenant are inconsistent with the fact that some members of the League contemplated a return to neutrality, as a result of the League being consistently ineffective in both preventing and controlling aggressive war. Denmark, Finland, the Netherlands, Norway, Spain, Sweden, and Switzerland each considered withdrawal; their complaints were valid. Japan and Italy had both resorted to war in defiance of the League before the Soviet Union was expelled for invading Finland in November of 1939. By then, however, the League was in its death throes and cataclysm was again upon the world.(Note 9)
During the period when the League was still functioning, efforts to clarify the law of neutrality continued. If nothing else, these efforts confirmed that the international community did not believe neutrality had passed into history.
The Convention on Maritime Neutrality concluded in Havana in February of 1928 again espoused impartial neutrality as the only true neutrality. Since it was signed by the United States in the same year that war was renounced as an instrument of policy in the Kellogg-Briand Pact, it testifies to the U.S. interpretation that the impartiality requirements of neutrality were essentially unchanged (at least for the United States and the other parties) by events and treaties after 1907.(Note 10)
Later in 1928, in an attempt to bring the power of the United States to bear, France proposed to conclude a bilateral treaty committing the United States to ensure French peace. Secretary of State Kellogg countered with an offer to join a multilateral treaty that would renounce war as an instrument of national policy. The result was the signing of the Kellogg-Briand Pact in August.(Note 11)
Though the Kellogg-Briand Pact was developed in response to a French effort to draw the United States into an alliance, it certainly restored some of the moral force U.S. policy had lost when the Senate refused to consent to ratifying the Treaty of Versailles and the League Covenant. The Pact was a far cry from a legal equivalent of the Covenant, however. Some even believed the Pact established a justification for unneutral acts by aggrieved parties when the Pact was violated by another.(Note 12) If this analysis is correct it would seem to permit the unneutral actions of the United States prior to the Japanese attack on Pearl Harbor, which brought the United States openly and completely into the war against the Axis. However, there does not seem to have been any appeal to the authority of the Pact to justify these actions.
This reaffirmation of strict neutrality precepts was perhaps foreseeable, but the question of when states should be aware of a state of war existing, and when belligerency became a legal status, giving rise to rights and obligations, remained difficult to answer in the interwar period as force not called "war" was being employed on a scale identical with war.
The political and legal restraints on resorting to war in the decades after World War I were defined by the League Covenant and the Kellogg-Briand Pact. Declaring war would constitute an invitation to sanctions under the Covenant and could affect the options of neutral states to provide assistance to both the victim and the aggressor. Consequently, weaker states fell prey to aggression in the form of undeclared war. According to Hindmarsh, "Probably more casualties and a greater variety of military actions occurred in the course of the Japanese peace-time invasion of Manchuria and Shanghai in 1931-1932 than many petty Balkan de jure wars."(Note 13)
This was the legal and political environment President Roosevelt encountered in 1933. Perhaps his later prewar decisions were foretold in his inaugural address when he said, "If I read the temper of the people correctly, we now realize as we have never realized before our interdependence on each other; that we cannot merely take but must give as well. "(Note 14) Options to "give" were politically limited because his administration took office during a period of strong domestic isolationist sentiment. This sentiment presumed an exceptionally favorable balance of power and a remarkable level of self-sufficiency, according to Manfred Jonas:
The isolationism of the thirties . . . sought only to preserve the American government's absolute control over its foreign policy by avoiding any long-term political commitments, either actual or implied, to other nations. They advocated a form of unilateralism, a policy of independence in foreign relations which would leave the United States free at all times to act according to the dictates of national self-interest.(Note 15)
More limitations were imposed by public opinion in the United States in the mid-thirties that ruled out the participation of the United States in another European war. The impact of the isolationists' attitudes and the support of the general populace for protracted neutrality probably had a byproduct antithetical to the objectives of the isolationists' philosophical approach. Other powers must have perceived that U.S. economic and military strength would not be brought to bear in response to aggression they might contemplate. The deterrent effect of the possibility of unneutral or co-belligerent action by the United States was greatly diminished.(Note 16) Not only did the isolationists ignore the effect of aggression on weaker states, they either failed to comprehend or resolved to endure the inevitable impact of that aggression on the United States as a result of its growing interdependence with the rest of the world.
The domestic political influence of the isolationists shaped the law of the land(Note 17) to conform with their philosophy. In the view of Manfred Jonas, this was to no avail:
In every existing conflict, and all those that could be foreseen, American neutrality legislation had the effect of aiding one side or the other. Since isolationists had tried to eliminate this dangerous contingency . . . their efforts to promote true neutrality through legislation must be considered a failure.(Note 18)
The world was to become increasingly embroiled in situations challenging the wisdom of impartial neutrality and inviting the dangers of unneutral involvement deemed essential to national interests. This environment set the stage for the war it foreshadowed.