Lea Mehari

Assistant Lecturer, School of Law, Addis Ababa University

Guerre 1939-1945. Bombe à hydrogène. Copyright Archives CICR (DR)

The first atomic warhead in the world was dropped on Hiroshima, Japan, 75 years ago today, August 6, 1945. An estimated 70,000 people died instantly. The total death toll was around 140,000. The survivors suffered cancer, chronic illnesses, as well as other radiation side effects for decades after. The bomb also damaged 70% of the city’s infrastructure. Three days later, August 9 1945, a second and larger atomic bomb exploded over the city of Nagasaki. The US justified its actions by invoking military necessity. It argued that dropping the bomb shortened the war by forcing the surrender of Japan and saved countless lives that would have been lost by a prolonged warfare. In his first speech after the Hiroshima bombing, U.S. President Harry S. Truman stated that the first atomic bomb was targeted at a military base and precautions were taken to minimize civilian deaths as much as possible. While Hiroshima had some military-related manufacturing plants, an army headquarters, and a military dock, it was disingenuous to characterize a city with more than a quarter-million civilians as just a “military base”. Just fewer than 10% of the civilians killed that day were part of the Japanese military. Besides, no precautions were taken to prevent civilian deaths.

Today, with all the IHL laws and Customary International Humanitarian Law rules, such nuclear weapons should be illegal. Nevertheless, there are many nuclear-weapon states that own nuclear weapons. Many more are currently developing nuclear weapons, a new threat against the restrictions on the means of warfare. Notwithstanding, the Treaty on the Prohibition of Nuclear Weapons, a treaty adopted by 122 states in 2017 and will become legally binding after 50 states ratify it (currently only 40 states have ratified it), will require them to reduce the number of nuclear weapons they have.

In 1996, the International Court of Justice (ICJ) issued a landmark advisory opinion on the legality of the Threat or Use of Nuclear Weapons. The ruling confirmed that there is neither customary nor treaty legal authority, which expressly forbids the possession or even use of nuclear weapons. The only prerequisite is that they are used in compliance with the international rules on self-defense and the principles of International Humanitarian Law (IHL).

Considering that the use of nuclear weapons is not explicitly banned by international law, there are concerns on whether the use of nuclear weapons contradict the provisions international conventions, customs or general principles of law that do not even address its use. This issue can be resolved by considering the implications of the use of nuclear weapons based on the fundamental principles of IHL.

The principle of humanity demands soldiers to mitigate the extent of suffering and damage caused by the war. Unnecessary suffering weighs the damage done by the weapon against the military necessity. Nevertheless, the principle of military necessity is not unlimited. It is recognized that IHL imposes limits on military necessity.  The mere existence of a military target does not allow limitless damage. The key issue here is not whether a specific weapon breaches international law, but whether the destruction caused or reasonably expected to be caused by a weapon is proportionate to the concrete military objective sought to be achieved by the attack. The principle of proportionality offers a valuable structure to determine the legitimacy of military strategies. It provides that, in using of nuclear weapons, there is no military need justifying the destruction of urban areas, mostly populated by civilians.  

A few people argue that nuclear weapons violate the St. Petersburg Declaration and the Hague Convention that provide for the principle of unnecessary suffering. While some agree that it is technically possible for a nuclear weapon to be used short of breaching this law, its real-life applications will cause detrimental extent of damage and suffering. A bomb that explodes amid civilians will cause deaths incidental to the military objectives obtained by its utilization. Even smaller nuclear weapons would be fundamentally unable to prevent such damages. Furthermore, the long-lasting impacts of nuclear weapons radiation on those exposed to it and their descendants is unnecessary for any military advantage. Ultimately, in the case of a nuclear attack, the environment will be a highly toxic area. Sufficient healthcare will also be difficult to find, leading to excessive suffering.

The principle of distinction would also be challenged by the use of nuclear weapons. It is well known in international law that civilians and civilian objects are immune from being directly targeted. Even though, some argue that it is technically feasible to use nuclear weapons in a way that prevents indiscriminate harm to civilians, it is doubtful that such usage would be possible. The use of nuclear weapons will also affect the territories of neutral nations. International law has important principles regarding neutral states. First, that belligerent parties cannot expand the battlefield to the territory of a neutral country, and, second, neutral states even have rights to prevent belligerent parties from entering their jurisdiction. The territory of a neutral State is inviolable; it cannot be absolved by using any of the conventional justifications in international law. The impact of nuclear weapons cannot be limited to the territories of a single country.

The Treaty on the Prohibition of Nuclear Weapons would ban nuclear weapons on the grounds of IHL and prohibits the production, testing, stockpiling, use or threat to the use of nuclear weapons. It aids the victims of the use and testing of nuclear weapons and encourages the remediation of contaminated sites. This also establishes mechanisms for a commitment by all States, including nuclear-weapon States, with the aim of the removal of all nuclear weapons.

Nuclear weapons are cruel and indiscriminate weapons. Their effects are devastating and have catastrophic humanitarian implications over generations. With the adoption of the UN Treaty on the Prohibition of Nuclear Weapons (TPNW), many states took a crucial step in building a nuclear-weapon-free future. It is now time to completely ban these weapons.  All states that have not yet done so should ratify this treaty, and save generations to come from the horrific consequences of a nuclear warfare.