Historical overview of international humanitarian law and weapons rules

The launch of the International Campaign to Ban Landmines in 1992 is usually seen as the beginning of humanitarian disarmament. However, the 1868 St. Petersburg Declaration banning explosive projectiles already shared some of the same humanitarian spirit, although it sought specifically to prevent the suffering of soldiers. The Declaration banned projectiles under 400 grams containing explosive or inflammable substances, recognising that such weapons would needlessly aggravate soldiers’ injuries or cause inevitable death.

The 1899 Hague Convention further codified the humanity principle by prohibiting the use of poisonous weapons and any weapons ‘of a nature to cause superfluous injury’¹. Two additional Hague Declarations prohibited ‘the use of projectiles the sole object of which is the diffusion of asphyxiating or deleterious gases’² and of ‘bullets which expand or flatten easily in the human body’, the so-called ‘dumdum bullets’³.

The 1907 Hague Conventions reiterated the above prohibitions. At that time civilians were usually far from the battlefield and rarely exposed to the effects of weapons, hence humanitarian concerns primarily addressed the excessively injurious effects of weapons on soldiers. The 1907 Hague Convention VIII also banned unanchored automatic contact mines, unless they deactivated within an hour, to protect merchant ships and fishermen. This logic of limiting the indiscriminate effects of weapons later contributed to the ban on anti-personnel landmines.⁴

After the extensive use of chemical gases during World War I and the development of aircraft, there was widespread public outcry and fears about the potential use of aero-chemical warfare in the future, particularly against civilians living in cities. This, together with the precedent of banning asphyxiating gases in the 1899 Hague Declaration, led to the adoption of the 1925 Geneva Protocol banning the use of asphyxiating and poisonous gases and bacteriological methods of warfare (see LU02). This prohibition on use was meant to protect both combatants and civilians against the pernicious effects of chemical weapons.⁵

During this period, IHL treaty-making was predominantly based on majority decisions. Although some great powers failed to ratify some of the treaties,⁶ this did not prevent them from becoming binding law among the rest of the states parties and over time their provisions have become norms of customary international law, binding even for states that have remained outside of the treaties.

After World War II, disarmament initially focused on WMD, starting with atomic weapons and later including biological and chemical ones. Although there were humanitarian concerns about the indiscriminate nature of WMD, security and strategic interests drove these discussions, resulting in the Biological Weapons Convention (BWC, 1971, see LU03) and the Chemical Weapons Convention (CWC, 1992, (see LU02)), with verification mechanisms included only in the latter.

Timeline of weapons-related IHL treaties

During this period, disarmament negotiations often hinged on great power agreement, which critics saw as a ‘game’ that was ‘institutionalizing the arms race’.⁷ In 1960, a special forum, the Ten-Nation Committee on Disarmament, a predecessor of the current Conference on Disarmament (CD), was set up to work on WMD and other weapons issues. Historically, a limited number of states have participated in this forum (from 10 in 1960 to 65 states of ‘key military significance’ today).⁸ The BWC, the 1968 Nuclear Nonproliferation Treaty (NPT, see LU05), the CWC and the 1996 Comprehensive Test Ban Treaty (CTBT) are among the treaties adopted by the Conference on Disarmament. Despite these achievements, the CD has remained dominated by the great powers and since the mid-1990s, its work has stagnated due to divergent state interests and consensus decision-making.

In the late 1960s and 1970s, conventional weapons and the need to develop IHL gained prominence on the international agenda, influenced by the Vietnam War and decolonisation. This led to the 1977 Additional Protocols (AP). As noted earlier, AP-I codified for the first time the principles of civilian protection that prohibited indiscriminate attacks.⁹ Several neutral and non-aligned states, led by Sweden, called for specific prohibitions on a range of conventional weapons to be included in the protocols. However, the major powers blocked conventional weapons bans within the protocols, leading to separate negotiations that produced the 1980 Convention on Certain Conventional Weapons (CCW). The CCW reconnected IHL with arms control during renewed Cold War tensions and became a precursor to later disarmament initiatives. The CCW includes an umbrella, framework convention and three weapons-specific protocols. Protocol I banned the use of any weapon whose primary effect is to injure by fragments which cannot be detected in X-rays. Protocol II restricted the use of remotely delivered mines whose location could not be recorded or those that did not have a self-neutralisation mechanism to render them harmless when no longer serving a military purpose. Protocol III prohibited the use of air-dropped incendiary weapons in populated areas, but allowed the use of ground-launched incendiaries if precautions to minimise civilian harm were taken. Without going into details, from an arms control perspective, the CCW became an uneasy compromise, combining IHL substantive rules and arms control decision-making procedures.

The CCW also included a clause that allowed future conferences to be convened to adopt amendments or new protocols. Fifteen years later, this clause was used to open new negotiations. These led to the 1995 Protocol IV prohibiting the use of laser weapons specifically designed to cause permanent blindness, and in 1996, to an amendment of Protocol II, which introduced additional safety and recording requirements for mines. However, the consensus decision-making inherited from the Cold War prevented agreement on the comprehensive prohibition of anti-personnel landmines that NGOs were seeking. This prompted Canada to launch a stand-alone negotiation process that resulted in the 1997 Mine Ban Treaty.

The CCW continues to serve as a forum for raising awareness of new weapons problems with input from NGOs. Thus, it can function as an indirect catalyst for action on new initiatives, but, given its consensus-based decision-making, can rarely adopt strict weapons prohibitions.

Footnotes

1. https://ihl-databases.icrc.org/assets/treaties/150-IHL-10-EN.pdf. ↩

2. https://ihl-databases.icrc.org/assets/treaties/165-IHL-13-EN.pdf. ↩

3. https://ihl-databases.icrc.org/assets/treaties/170-IHL-14-EN.pdf. ↩

4. https://ihl-databases.icrc.org/en/ihl-treaties/hague-conv-viii-1907?activeTab=default; Vagts 2000, 36. ↩

5. See, for example, Price 1997. ↩

6. For example, the US never signed the 1899 Hague Declarations banning asphyxiating gases and expanding bullets. ↩

7. Myrdal 1978, 169. ↩

8. https://disarmament.unoda.org/conference-on-disarmament. ↩

9. See Alexander 2016; Mantilla 2020, 2023; Petrova forthcoming, chapters 3–6. ↩