[From The Control of Chemical and Biological Weapons, Carnegie Endowment for International Peace, New York, 1971]

LEGAL ASPECTS OF THE

GENEVA PROTOCOL OF 1925

by R. R. Baxter and Thomas Buergenthal

In his policy statement of 25 November 1969, on chemical and biological warfare, President Richard M. Nixon declared that the Administration would ask the Senate for advice and consent to the ratification of the Geneva Protocol of 1925. At the same time, the President reaffirmed the renunciation by the United States of "the first use of lethal chemical weapons" and extended "this renunciation to the first use of incapacitating chemicals." With regard to biological weapons, the President renounced the use of all biological weapons and methods of warfare; declared that the United States would confine its biological research to defensive measures; and ordered the Defense Department to make recommendations for the "disposal of existing stocks of bacteriological weapons." On 14 February 1970, the President extended the ban on biological weapons to include toxins.*

Crucial to any meaningful assessment of present or future United States policy in this field is an understanding of the

* Subsequently to the completion of this paper, the President of the United States on 19 August 1970 transmitted the Geneva Protocol of 1925 to the Senate for its approval. In the report of the Secretary of State, which was transmitted with the President's letter, the Secretary of State proposed a reservation asserting the right of the United States to use chemical weapons in retaliation against an enemy state failing to observe the obligations laid down in the Protocol and explained that it is the understanding of the United States that the Protocol "does not prohibit the use in war of riot-control agents and chemical herbicides." [U.S. Dept. of State Bulletin, Vol. 273 (1970), p. 63.]

The Senate may, of course, make its own determinations about reservations and understandings with respect to a treaty submitted to it.

legal scope of the Geneva Protocol. This paper will accordingly describe the obligations the Protocol imposes, what steps the United States will have to take if it decides to become a party to the Protocol without accepting all of its obligations, and what legal problems it will encounter in doing so.

The Prohibitory Scope

of the Geneva Protocol of 1925

2

The Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare was signed at Geneva on 17 June 1925.1 It has been formally ratified by or is otherwise binding upon eighty-five nations, including all the major military and industrial nations of the world except for the United States. Although the United States government participated in the drafting of the Geneva Protocol and signed it,3 the Senate failed to give its consent to the ratification of the treaty.*

The Geneva Protocol prohibits two things: (a) “the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices," and (b) “the use of bacteriological methods of warfare.” It does not prohibit the production, acquisition, or stockpiling of these weapons, nor does it apply to their use for purposes other than in "war." This means, among other things, that the testing of these weapons is not proscribed by the Geneva Protocol; the same is true of the manufacture of equipment capable of dispersing them.

The major question that has arisen with regard to the interpretation of the Protocol is whether irritant chemicals (tear gas) and anti-plant chemicals fall within the prohibition of the use in war of "asphyxiating, poisonous or other gases." Before that question can be answered, we must be clear about the manner in which the meaning of a doubtful passage in a treaty is determined.

Treaties are to be interpreted "in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose." There may also be taken into account the subsequent practices of the

6

parties establishing their agreement on its interpretation. And if the meaning of the agreement is still ambiguous or obscure, one may turn to the preparatory work of the treaty and the circumstances of its conclusion."

It is important to notice in this connection that it is the subsequent practice of the parties that may be taken into account. This suggests that the interpretation attached to the Protocol by the United States, a non-party, carries much less weight than some have assumed. A certain amount of confusion has been occasioned by a failure to distinguish evidence that goes to the interpretation of the Protocol from evidence of the state of customary international law. The reach of the treaty prohibition of chemical warfare is not necessarily coextensive with the corresponding prohibition found in customary international law. In other words, it may well be that the Geneva Protocol-the treaty or conventional prohibition outlaws all forms of chemical warfare, including irritant chemicals and anti-plant chemicals. This does not mean, however, that as sweeping a prohibition need necessarily have passed into customary international law as a rule binding on all states, whether or not parties to the Protocol.

Unless one recognizes that the reach of the conventional and the customary international law rules need not be identical, it is impossible to determine from the available negotiating history and subsequent practice what forms of chemical warfare the Geneva Protocol was intended to outlaw. For what might be regarded as legally conclusive evidence to support a sweeping interpretation of the Geneva Protocol can, and in fact does, become much less conclusive for purposes of ascertaining the full scope of the customary rule. Thus, although the chemical warfare practice and declarations of states not parties to the Geneva Protocol are relevant evidence for the purpose of delimiting the scope of the customary rule, they do not bear witness to the scope of the conventional rule. If one is guided by this principle in analyzing the chemical warfare prohibition of the Geneva Protocol, many of the doubts regarding its intended scope disappear.

A. Irritant Chemicals

The prohibition of the Protocol that deals with chemical warfare is self-explanatory, at least to the extent that it outlaws the use of "asphyxiating" and "poisonous" gases and "all analogous liquids, materials or devices." The doubt as to the full scope of the prohibition, which in its English text-"or other gases"-could hardly have been expressed in more sweeping and all-embracing language, results from the fact that the French text of the Protocol speaks of "gaz asphyxiantes, toxiques ou similaires." On the debatable premise that the use of the word "similaires" in the French text limits the prohibitory scope of the Protocol, 10 it has been suggested that the Protocol applies only to chemical agents having harmful consequences similar to those of asphyxiating or poisonous gases." Leaving aside the question whether this restrictive interpretation is scientifically or medically meaningful, particularly when applied to the military uses of chemicals, the fact remains that the slight difference between the English and French texts of the Protocol has been used to support the argument that certain chemical weapons, such as tear gas and herbicides, do not come within the prohibition of the Protocol. Relying on this textual ambiguity, the United States government has argued that "it would be unreasonable to contend that any rule of international law prohibits the use in combat against an enemy, for humanitarian purposes, of agents that Governments around the world commonly use to control riots by their own people."2 Similar contentions have been made with regard to the use in war of anti-plant chemicals.

1. The history of the chemical warfare prohibition in the Geneva Protocol. The language in which the Geneva Protocol proscribes the use of chemical weapons is found in a number of earlier treaties. 13 These attempts to outlaw chemical warfare reflected the abhorrence and outrage with which the international community reacted to the use of gas in the First World War. Among the different gases used by both sides in that war were various types of lachrymatory (tear) gases. The massive use of lachrymators-it is estimated that 12,000 tons of this gas were employed-suggests that the draftsmen

14

58-743 - 72 - 9

of these treaties were well aware of the military uses of irritant chemicals.

(a) The Treaty of Versailles. The first international treaty to use the terminology employed in the Geneva Protocol was the Treaty of Versailles.15 It provided in Article 171 that "the use of asphyxiating, poisonous or other gases and all analogous liquids, materials or devices being prohibited, their manufacture and importation are strictly forbidden in Germany." (Emphasis supplied.) The French text of Article 171 used the word "similaires,” which is also true of all subsequent treaties that adopt the formula found in the Geneva Protocol. What meaning the draftsmen of the Versailles Treaty attached to this formula is not clear,16 because they did not discuss its meaning. That little significance can be attached to the slight divergence between the English and French texts of Article 171 is apparent, moreover, from the language of Article 172 of the Treaty. It required Germany to disclose to the allies "the nature and mode of all explosives, toxic substances or other like chemical preparations used by them in the war. . . .' The French text of Article 172 renders the more restrictive "or other like chemical preparations" simply as “ou autres préparations chemiques."

(b) Treaty on Submarine and Gas Warfare. The Treaty on the Use of Submarines and Noxious Gases in Warfare, signed in Washington in 1922 by France, Great Britain, Italy, Japan, and the United States," provided in Article 5 that:

The use in war of asphyxiating, poisonous or other gases, and all analogous liquids, materials or devices, having been justly condemned by the general opinion of the civilized world and a prohibition of such use having been declared in treaties to which a majority of the civilized Powers are parties,

The Signatory Powers, to the end that this prohibition shall be universally accepted as a part of international law binding alike the conscience and practice of nations, declare their assent to such prohibition, agree to be bound thereby as between themselves and invite all other civilized nations to adhere thereto.

Although the Treaty of Washington never entered into force because France failed to ratify it, it was ratified by the