ABSTRACT
The objective of this book was to identify the essential character of the traditional law of neutrality by reconsidering its historical development, thereby gaining a perspective that would resolve the various issues regarding the current status of the law of neutrality. While resolving these issues regarding the current
status of the law of neutrality is a matter for further research, based on the analysis of this book, we can present some guidelines for resolving these issues. As noted in section 1 of the Introduction, as regards the current status of the law of neutrality, contemporary scholars have debated whether it is lawful for a State to take a position of “non-belligerency”: “the situation of those States which, while not wishing to enter the conflict on the side of one belligerent, do not, at the same time, choose to be bound by traditional neutrality obligations”.3 While the views of scholars differ as to the legality or illegality of attitudes of “non-belligerency”, they have shared some assumptions about the traditional law of neutrality. However, as some of these assumptions have been revised by the analysis of this book, the debates on the current status of the law of neutrality should also be reorganised. One of the grounds for those writers who affirm the legality of attitudes of “non-belligerency” is that the historical foundation of the “duty of impartiality” was the equality of belligerents as a consequence of the unrestricted freedom of States to resort to war, and that such a basis has disappeared as a result of the outlawry of war. However, as identified in this book, the basis of the so-called “duty of impartiality” in the traditional law of neutrality was not the equality of belligerents. As acts contrary to the “duty of impartiality” were regarded as acts equivalent to “acts of war” or “the participation in the war”, a State wishing to remain outside the war should abstain from those acts. But such acts were not prohibited in traditional international law. Certainly, belligerents were equal in traditional international law, where resort to war was not prohibited, but third States were not prohibited from assisting a belligerent either by entering the war or without entering the war. Such assistance should be abstained from if a State wished to remain neutral, but those States not wishing to avoid being involved in the war did not need to abstain from those acts. In short, the view that affirms the legality of attitudes of “non-belligerency” in contemporary international law has been based on a mistaken assumption about the historical basis of the traditional law of neutrality. On the other hand, it is not the case that those writers who deny the legality of attitudes of “non-belligerency” have assumed the correct understanding of the traditional law of neutrality. The ground for this view is the continuing validity of the traditional law of neutrality, in which States that do not take part in a war automatically become neutral States and are bound by the duty of impartiality. However, according to the analysis of this book, in the traditional law of neutrality, acts contrary to the “duty of impartiality” were not prohibited, but such acts should be abstained from if States wished to remain outside the war. In traditional international law, it was not prohibited for third States that did not claim the right to remain neutral to provide military assistance to either belligerent. That being so, we cannot argue that attitudes of “non-belligerency” are illegal, based solely on the continuing validity of the traditional law of neutrality. Based on the analysis of this book, the issue to be discussed regarding the current status of the law of neutrality is not the legality or illegality of attitudes
of “non-belligerency”. Attitudes of “non-belligerency”, that is, attitudes of States that provide military assistance to a belligerent without entering the war or international armed conflict, which were legal in traditional international law, seem to be still legal in contemporary international law based on the right of collective self-defence (Article 51 of the United Nations Charter). Rather, the issue to be debated is the legal consequences of attitudes of “non-belligerency” as opposed to the status of neutrality: What are the legal advantages of choosing the status of neutrality as compared to taking attitudes of “non-belligerency”? In other words, the issue to be discussed in further research is whether the law of neutrality, which was the institution that legally protected the right of neutral States not to be involved in war, has any legal relevance in contemporary international law. In the traditional law of neutrality, a belligerent was permitted to “treat as an enemy” a third State violating neutrality; on the contrary, a third State that observed neutrality was legally entitled not to be “treated as an enemy”. To be treated as an enemy means being treated as a belligerent. If a hitherto neutral State is treated as an enemy and becomes a belligerent, the following two consequences follow. First, the territory of that State becomes regions of war, in which belligerent States may conduct hostilities (belligerents are not permitted to conduct hostilities in the territory of neutral States). Second, merchant vessels and cargoes of that State become enemy vessels and enemy cargoes, which are subject to seizure and confiscation by belligerents (neutral vessels and cargoes are not subject to seizure and confiscation except in cases of the transportation of the contraband of war, the breaches of blockade, or engaging in unneutral service etc.). The issue is to what extent the framework of the traditional law of neutrality is applicable in contemporary international law and whether the traditional law of neutrality has any value in contemporary international law. A “nonbelligerent” State, which provides military assistance to a belligerent, would be treated as an enemy by the other belligerent if we applied the framework of the traditional law of neutrality. However, the issue is whether the aforementioned two consequences would follow with regard to a non-belligerent State in contemporary international law. As regards the first consequence, in modern international law where the use of forces by States in international relations is prohibited in principle, acts of hostilities or the use of force do not automatically become legal even if “war” breaks out; rather, each act of hostility or the use of force should be evaluated with reference to the justifying grounds of the use of force such as the right of self-defence. In other words, the concept of “war” is legally irrelevant in relation to the principle of the non-use of force.4 That being so, when evaluating the legality of hostilities conducted by belligerent States against non-belligerent States in contemporary international law, the framework of the traditional law of neutrality seems to have little relevance, and it might be sufficient to apply the framework of the principle of non-use of force and its exceptions (self-defence, etc.). In other words, the law of neutrality, as an institution that legally protects the status of neutral States to remain outside
the war, might be absorbed into the principle of non-use of force in contemporary international law. However, recalling that, in State practice during the Second World War, the legality of wars and hostilities against neutral States (Norway, the Netherlands, Belgium) by belligerent States (Germany and Great Britain) was debated not relying on the framework of the prohibition of war by the Pact of Paris and the right of self-defence as an exception to that, but relying on the framework of the law of neutrality,5 there may be room for the law of neutrality to function as a framework for the legal regulation of the use of force by belligerents against third States. On the other hand, as regards the second consequence, the law of neutrality may not be absorbed into the principle of non-use of force. The issue of whether belligerent States (States party to an armed conflict) should treat the vessels and cargoes of non-belligerent States as enemy vessels and cargoes or as neutral vessels and cargoes cannot be resolved by applying the principle of the non-use of force, and thus the traditional law of neutrality still has legal relevance in contemporary international law.6
