The Problematic Legality of Tear Gas Under International Human Rights Law (2020) by Natasha Williams, Maija Fiorante and Vincent Wong comments
The use of tear gas has exploded recently, as people have gathered en masse in the U.S. and around the world to protest racial injustice and police brutality in the wake of the killing of George Floyd at the hands of Minneapolis police. In order to suppress these protests, tear gas has been used in large quantities and in questionable ways by police in Minneapolis, Seattle, Los Angeles, Washington, Philadelphia, and Montreal, among other cities. Globally, tear gas has been a popular law enforcement option to crackdown on protests in many regions, from France to Chile, Turkey to Hong Kong. In one recent high profile deployment, tear gas was used to clear a peaceful crowd outside the White House so U.S. President Donald Trump could take a photo at a church across the street.
Despite its prohibition in warfare, not all uses of tear gas are illegal under the current state of international human rights law. In fact, the international protocol governing chemical weapons has been explicitly interpreted by many countries to allow for the use of tear gas in law enforcement. However, tear gas should be banned under international human rights law.
Used as an area weapon, tear gas is indiscriminate in its effects — it harms everyone in its vicinity regardless of whether one is engaged in militant actions in a demonstration, protesting peacefully, or merely observing. Although international guidance exists, including UN guidelines on the use of less-lethal weapons, these non-binding documents are vague and ineffective in curtailing violations, giving rise to a situation where tear gas is systematically prone to misuse. These factors make tear gas inherently inappropriate and dangerous to use. The use of tear gas is rightfully banned in warfare, and should equally be banned as a riot control agent in domestic contexts.
The authors noteHistorically, tear gas has had a particularly close connection with severe human rights violations and torture. Banning tear gas under international human rights law will ensure that tear gas will no longer be deployed inappropriately, causing unnecessary harm and injury, nor will it be further used to unduly extinguish freedom of speech and freedom of assembly.
In the law of war, where far greater leeway is given to the use of deadly force, tear gas is forbidden. Given this, it is illogical to continue to allow for its use by domestic law enforcement as a riot control agent.
The first international attempt at banning tear gas, among other chemical and biological weapons, was convened by the League of Nations and produced the Geneva Protocol of 1925.
The Protocol bans “the use in war of asphyxiating, poisonous or other gases”. Tear gas could potentially fall into any of the three impugned categories, but the text itself is not specific and does not spell out exactly which agents are prohibited and which are not. While many countries endorsed the interpretation that tear gas was banned under the Protocol, the U.S. used the vagueness of the text to assert that it was not, leading to its widespread use in the Vietnam War.
The Chemical Weapons Convention, an International Humanitarian Law (IHL) agreement binding on 193 states parties, was intended to be a stronger treaty than the 1925 Geneva Protocol by banning the use of chemical weapons entirely in war. While it reaffirmed the principles and objectives of the Protocol, the Convention goes much further than its predecessors in prohibiting riot control agents (RCAs). However, the Convention carves out exceptions for the use of RCAs by law enforcement. While the use of RCAs as a method of warfare is considered a direct violation, the Convention explicitly exempts the use of RCAs, including tear gas, for law enforcement purposes such as domestic riot control.
One rationale for this exception can be traced back to the Convention’s negotiations, which indicate that the terms were deliberately changed in order to achieve a more widespread acceptance of the Convention. In particular, the terms governing RCAs were controversial for the United States. Thus, these terms were deliberately broadened to allow for the possibility of domestic and non-domestic use of RCAs by law enforcement.
The Convention remains ambiguous on its definitions of permitted “law enforcement” and prohibited “method of warfare,” raising questions regarding exactly when tear gas use is permitted or banned under the Convention. The Convention is also silent on “types” and “quantities” of RCAs permitted. States parties have consequently interpreted this as they see fit. For instance, the United States, under the Clinton administration, interpreted the Convention’s provisions as not prohibiting the use of RCAs in riot control situations in areas under direct U.S. military control, including rioting by prisoners of war, and protecting convoys from terrorists in areas outside the zone of immediate combat. For the U.S., the use of RCAs solely against noncombatants for law enforcement, riot control, or other noncombatant purposes would not be considered as a “method of warfare” and therefore would not be prohibited. Furthermore, uses of RCAs outside of international or internal armed conflict were seen as being unaffected by the Convention. The Convention was interpreted as not applying to peacetime uses, such as peacekeeping operations, law enforcement operations, humanitarian and disaster relief operations and noncombatant rescue operations conducted outside of international or internal armed conflicts. In contrast to the United States, the United Kingdom considers RCAs a method of warfare and thus prohibited by the Convention.
Despite the development and the ratification of the Convention, the leading international protocol on chemical weapons, there remain significant gaps in the governance on tear gas, enabling law enforcement bodies to exploit these ambiguities for their own interests. A complete ban on tear gas would resolve these discrepancies in the interpretation of the Convention.
Another rationale offered for the disparity between legal treatment within and outside zones of conflict suggests that tear gas and other RCAs are banned in warfare because they don’t discriminate between combatants and noncombatants. However, according to this line of reasoning, tear gas should also be banned for use by domestic law enforcement. Tear gas cannot distinguish between the young and the elderly, the healthy and the sick, the peaceful and the violent. It causes myriad health harms regardless of whether someone is a rally goer or a bystander. The legal exception for use of RCAs in domestic law enforcement can therefore best be explained as a matter of political expediency during treaty negotiations. There is little in the way of a principled human rights rationale to support the domestic use of RCAs against one’s own citizens. Moreover, the prohibition of tear gas in warfare establishes the norm that tear gas is a harmful weapon whose use is not even acceptable during war. This norm is reaffirmed by Article 8 of the Rome Statute of the International Criminal Court, which includes several provisions governing the use of chemical weapons in armed conflict. Specifically, Articles 8(2)(b) and 8(2)(e) provide that the employment of “poisoned weapons” and “asphyxiating poisonous or other gases, and all analogous liquids, materials or devices” constitute war crimes, both in international and non-international armed conflict. Although the Statute does not explicitly mention tear gas, it is likely that these provisions encompass tear gas, as the agent would fall under “other” or “analogous” poison gas. Tear gas is banned on the battlefield and should be banned in peacetime as well.
