International Humanitarian Law and the Conduct of War

To avoid any mix-up or confusion, it is necessary to clarify the similarities and differences between International Humanitarian Law (IHL), Human Rights Law (HRL) and International Criminal Law (ICL). While IHL, HRL and ICL are key features of international law, there are differences in their provision and application.

Human Rights Law

Human Rights Law (HRL), or International Human Rights Law, protects the universal rights of all people everywhere regardless of race, religion, gender, or other differences. These rights are fundamental: every human being is entitled to them and they cannot be removed. Behind this idea lies the principle that all human beings have inherent dignity and worth simply by virtue of being human. Such an approach means that human rights are universal, inalienable, and indivisible.

International Humanitarian Law (IHL) is not a substitute for Human Rights Law. While both laws share some common objectives, such as the protection of individuals, there are also important differences between them.

Firstly, human Rights Law always applies, while International Humanitarian Law has a more narrow focus, as it applies only during armed conflicts. That is why IHL is often referred to as “the law of armed conflict”. Human Rights Law provides more extensive protection for individuals, including economic, social, and cultural rights.

The most important human rights instrument is the Universal Declaration of Human Rights, adopted in 1948 by the General Assembly of the UN.

While IHL and HRL have specific norms, the main similarity is their common goal: the protection of the individual. This protection covers, among other things, people’s physical and mental integrity, and human dignity. So while distinct, they are complementary frameworks with a common spirit at their core - shielding human life and dignity from violence and deprivation.

International Criminal Law

The principles and rules of International Criminal Law (ICL) have been developed over the years by international legal institutions. These include the International Criminal Tribunal for the Former Yugoslavia (ICTY), the International Criminal Tribunal for Rwanda (ICTR) and the International Criminal Court (ICC). The 1998 Rome Statute, which created the International Criminal Court, is the cornerstone of the current ICL framework. 123 states have ratified or acceded to the Statute as of 2023.

International Criminal Law enables the prosecution and punishment of individuals for particularly serious international crimes. These crimes include genocide, war crimes, and crimes against humanity. ICL applies at all times, during both war and peace. It holds both states and individuals criminally responsible for these grave breaches of international law that deeply offend human dignity.

While international criminal law establishes accountability for grave crimes, its application relies on state cooperation. Many countries have not ratified the Rome Statute which established the International Criminal Court, meaning perpetrators in those nations cannot be tried at the ICC without a UN Security Council referral.

While International Humanitarian Law aims to regulate the means and methods of warfare to reduce human costs, ICL focuses on criminal offences through prosecution. Their main differentiating point is thus their focus: IHL on the victim, and ICL on the perpetrator.

The difference between Human Rights Law and International Criminal Law also revolves around its focus. Human Rights Law takes a comprehensive approach aimed at promoting and protecting the full spectrum of human rights globally. For example, HRL covers rights to education, health, free speech and assembly that should be upheld for all people. ICL, on the other hand, is concerned with accountability and justice for four specific acts that constitute international crimes - genocide, crimes against humanity, war crimes and crimes of aggression.

International humanitarian law (IHL) aims to strike a balance between military necessity and considerations of humanity. To achieve this goal, IHL establishes three core principles: Distinction, Proportionality, and Precaution.

Principle of Distinction

The principle of distinction requires parties to a conflict to distinguish between those participating and those not participating in hostilities. Specifically, those involved in warfare - including combatants, commanders, and strategists - must discriminate between combatants and non-combatants such as civilians, the sick, wounded, or captured. This means civilians or anyone who is not a combatant should not be attacked. By distinguishing participants from non-participants, the principle of distinction aims to limit the effects of armed conflict and protect those not involved in hostilities. 

International Humanitarian Law strictly protects prisoners of war (POWs). The principle of distinction requires POWs to be treated humanely and their dignity respected, despite being captured enemies. IHL absolutely prohibits any ill-treatment, violence, or cruelty against POWs. It mandates they receive adequate food, shelter, medical care and communication rights. 

Many acts are considered violations of the dignity of Prisoners of War (POWs) under IHL.

These, amongst many others, include:

 • Torture and Cruel Treatment: Inflicting physical or mental harm, torture, or subjecting POWs to inhumane treatment.

 • Humiliating or Degrading Treatment: Subjecting POWs to humiliating acts, such as forcing them to perform degrading acts, using derogatory language, or public humiliation.

 • Denial of Proper Medical Care: Failing to provide adequate medical attention and care to sick or injured POWs, or denying them access to necessary medical treatment.

 • Forced Labour or Slavery: Forcing POWs to engage in forced labour, servitude, or any form of slavery.  

 • Denial of Basic Needs: Withholding essential supplies like food, water, shelter, and clothing from POWs.

 • Forced Propaganda or Ideological Indoctrination: Coercing POWs to make statements against their will, or subjecting them to forced ideological indoctrination or interfering with their freedom of thought.

While combatants and military targets may lawfully be attacked during armed conflict, such attacks must only be directed at concrete and direct military objectives that offer a definite military advantage. All participants in warfare are required to take precautionary measures in the way they conduct the war and respect the principle of proportionality.

Principle of Proportionality 

The principle of proportionality suggests that all military attacks must be proportionate to the threat. An attack that causes excessive incidental damage in relation to the anticipated military advantage would be considered disproportionate under International Humanitarian Law. 

There are historical examples of ‘disproportionate’ attacks carried out by countries in violation of IHL. One of these is the bombing of the city of Guernica^[6] during the Spanish Civil War in 1937. The attack was conducted by the German Luftwaffe, supporting General Franco's nationalist forces against the Republican government. Within three hours, these bombings caused widespread destruction and killed between 250 and 300 civilians. It was widely regarded as a disproportionate and indiscriminate act of aggression, which violated the principles of distinction and proportionality under IHL, failing to distinguish between combatants and civilians or to adhere to any standard of proportionality in the attack.

Another example of a “disproportionate attack” occurred in the 2008-2009 Gaza War between Israel and Hamas. In response to indiscriminate rocket attacks by Hamas from the Gaza Strip, Israel launched a military operation that involved airstrikes and artillery shelling, targeting various sites in Gaza. Critics argued^[7] that Israel's response was disproportionate because the extent of damage and civilian casualties caused by its attacks seemingly exceeded the threat posed by Hamas' rocket fire. The United Nations and various human rights organisations raised concerns about the high number of civilian casualties, including women and children, and the destruction of infrastructure.

In these two examples, determining what constitutes a ‘disproportionate’ attack is a complex and contentious issue. 

Principle of Precaution

The principle of precaution requires parties to armed conflicts to select and implement methods of warfare with care and caution. This principle underlies many of the rules in international humanitarian law (IHL) that prohibit certain unethical methods of warfare. 

The principle of precaution emphasises the need to minimise the harm inflicted on civilians and civilian objects during military operations. In essence, the principle is a practical way of resolving or managing the tension between the ‘principle of military necessity’ and the ‘principle of proportionality’ to ensure hostilities are conducted in a humane way.

This means all military actions should be planned and executed in a measured way. Under this principle of precaution, military commanders are required to assess the potential risks and consequences of their military actions. It is their obligation to ensure that any anticipated harm to civilians is proportionate to the military advantage they seek to gain from any action. 

In practical terms, this requires choosing means and methods of warfare that minimise harm to civilians and refraining from using unethical or inhumane methods. A few different methods fit this description: the use of perfidy, terror, famine, pillage, or hostage-taking, for instance. Similarly, weapons that can cause superfluous injury, unnecessary suffering or indiscriminate harm or casualties, are prohibited under IHL. 

The Geneva Conventions and their Additional Protocols are the key treaties that prohibit these unethical methods of warfare. 

Nation-states, individuals, military commanders, members of the armed forces, organised armed groups and international organisations can be prosecuted for war crimes under IHL. IHL offers personal protection to everyone, including Prisoners of War (POW), members of the armed forces, civilians, combatants, and those who no longer participate in hostilities. 

A core aim of International Humanitarian Law is to preserve human life and dignity even amid the devastation of war. To that end, IHL establishes protections for individuals most vulnerable to suffering and mistreatment during armed conflict. 

International Humanitarian Law (IHL) is codified in several key treaties that aim to regulate the conduct of parties during armed conflict and protect victims of war. The main IHL treaties are:

The Four Geneva Conventions of 1949

 • Geneva Convention I - Protects wounded and sick members of the armed forces in the field.

 • Geneva Convention II - Protects wounded, sick, and shipwrecked members of armed forces at sea.

 • Geneva Convention III - Relates to prisoners of war.

 • Geneva Convention IV - Protects civilians, including those in occupied territory.

These four conventions form the backbone of IHL. They provide protection for different categories of persons during international armed conflicts between nation-states. The first two conventions protect sick, wounded and shipwrecked military personnel. The third Geneva Convention outlines standards for the humane treatment and rights of prisoners of war (POWs). The fourth critically protects civilians from the impacts of conflict.

Each convention has its own articles specific to protections for that category, but Articles 1, 2, and 3 are common across all four conventions.

Article 1 states that the Geneva Conventions must be applied in any official declaration of war or armed conflict between two or more countries. The Conventions set out protections for people not involved in fighting, such as civilians, aid workers, and medical personnel.

Article 2 says the Conventions also apply to fighting within a country between government forces and rebel groups. This ensures the protections cover civil wars and other internal conflicts, not just wars between nations.

Article 3 is identical in all four Geneva Conventions. It establishes basic minimum standards that must be followed in all conflicts, even civil wars. These minimums include:

 • Humane treatment for those not participating in hostilities

 • No torture or degrading treatment

 • Fair trials for anyone facing criminal charges

Article 3 was groundbreaking because it set a baseline of human treatment and a standard for human dignity in conflict to be applicable universally, both in international and internal conflict.

Additional Protocols of 1977

The Geneva Conventions of 1949 brought major improvements in the protection of victims of conflict under International Humanitarian Law. They left some situations untouched, however: the Geneva Conventions covered essentially conflicts between states, and internal conflicts within a state’s border, such as civil wars, were mostly treated superficially. Only Article 3, common to all four conventions, referred to internal conflicts.

Moreover, technological advances in warfare since 1949 highlighted gaps in protections. New weapons and tactics had emerged, including increased air bombings, that caused humanitarian concerns. In addition, this new international discussion on IHL represented an opportunity for countries that were not independent in 1945 to contribute to the development of the Law.

 • Additional Protocol I - Covers international armed conflicts. Further protects civilians and combatants by clarifying the principle of distinction.‍

 • Additional Protocol II - Relates to non-international armed conflicts specifically and protects victims of these specific battles.

These protocols supplement the four Geneva Conventions of 1949. Additional Protocol I strengthened the protections for civilians and combatants in international conflicts. Protocol II extended core IHL protections to internal armed conflicts between states and non-state groups. The Additional Protocols of 1977 thus addressed gaps in international humanitarian law left by the 1949 Geneva Conventions.

Definition of Weapons of Mass Destruction (WMD)

Weapons of Mass Destruction (WMD) are weapons that can cause significant harm or damage to large numbers of people, infrastructure, or the environment. Such weapons include nuclear, chemical, radiological and biological weapons. The use of WMDs is prohibited by international law, and several treaties and agreements are in place to control their development, production, and use.

Chemical weapons use toxic agents like nerve gas or mustard gas to poison and kill a high number of individuals. Biological weapons involve bacteria, viruses or toxins which are weaponized to cause deadly disease outbreaks. Radiological weapons combine radioactive material with conventional explosives to disperse dangerous radiation over large areas. Finally, nuclear weapons harness fission or fusion reactions for immense destructive blasts that have become more and more dangerous with the progress of technology. 

Each type of WMD poses unique risks - they can inflict mass casualties, cause long-term health effects, disrupt societies, demand specialised defences, and enable groups or nations with malicious intent to terrorise populations if acquired. Their use is prohibited under international law through treaties like the Hague Code of Conduct, the Chemical Weapons Convention, and the Nuclear Non-Proliferation Treaty.

International Treaties against Weapons of Mass Destruction (WMDs)

There are several international treaties and agreements in place to control the development, production, and use of Weapons of Mass Destruction (WMD).

The Hague Code of Conduct (HCOC) is a voluntary, non-binding international agreement that seeks to prevent the proliferation of ballistic missiles capable of delivering WMDs. The HCOC was adopted in 2002 and has been signed by 139 countries. The Code of Conduct establishes guidelines for the responsible behaviour of states in the development, testing, and deployment of ballistic missiles. The Code also aims to promote transparency and confidence-building measures between participating states.

Countries such as North Korea, Pakistan, China, Iran, and Syria have not yet signed the HCOC. By not signing this agreement, these countries are not subject to the specific obligations and commitments outlined in the code. That means, for one thing, that they do not have to provide information on their ballistic missile programmes. The resulting lack of transparency can lead to regional tensions and concerns about the proliferation of WMDs. These countries may also face diplomatic pressure, scrutiny, or potential sanctions from other signatory states or the international community, as is the case with Iran.

Iran began developing ballistic missiles in the 1980s during the Iran-Iraq war. It claims its missile program are for defensive purposes only, but critics allege Iran's missiles could deliver nuclear warheads if Iran develops them in the future, threatening regional security.

In conjunction with the HCOC, the United Nations (UN) also plays a significant role in disarmament efforts related to weapons of mass destruction. The UN has established several other treaties and conventions aimed at controlling the development, production, and use of WMDs. One of the most important of these treaties is the Chemical Weapons Convention (CWC), which prohibits the development, production, stockpiling, and use of chemical weapons. The Convention was adopted in 1993 and has been ratified by 193 countries.

The CWC requires participating states to destroy their existing chemical weapons stockpiles and production facilities, and to declare and destroy any chemical weapons they may discover in the future. The Organisation for the Prohibition of Chemical Weapons (OPCW) is responsible for implementing the Convention and conducting inspections of states' facilities and activities related to chemical weapons.

The production and stockpiling of chemical weapons pose serious dangers to global security - as these weapons can cause indiscriminate and significant harm to people. Nevertheless, the execution of the CWC and other WMD-related treaties is not entirely free of difficulties.

A historical example of these controversies is the false accusations regarding weapons of mass destruction (WMDs) used to justify the Iraq War in 2003. The United States, the United Kingdom, and their allies claimed that Iraq, under the leadership of Saddam Hussein, possessed and was actively developing WMDs, including chemical weapons. These claims were used to justify military action against Iraq. It later turned out that the allegation was not only unfounded, but was based on incorrect intelligence.^[8] No evidence of possession, production or stockpiling of WMDs was found in Iraq.

The US-led invasion of Iraq has been blamed for causing unnecessary loss of life and infrastructure. The war has had far-reaching effects on both Iraq and the global community, stirring up sectarian tensions in Iraq and a prolonged period of violence and instability in the region.

The UN also established the International Atomic Energy Agency (IAEA) in 1957, which is responsible for verifying states' compliance with the Nuclear Non-Proliferation Treaty (NPT). The NPT aims to prevent the spread of nuclear weapons and technology and to promote peaceful uses of nuclear energy.

It is important to note that while nuclear weapons are primarily designed for destructive purposes, the energy produced by nuclear reactions can be used for beneficial purposes. Examples of these are nuclear power plants used to generate electricity. Nuclear technologies are also used in medical diagnosis and treatment. The technologies can also be employed in agriculture to develop new, disease-resistant crops through a process called mutation breeding.

The Nuclear Non-Proliferation Treaty has been signed by 191 countries since 1968. It is one of the most important disarmament treaties in the world. Under the NPT, countries are divided into two categories - nuclear-weapon states (NWS) and non-nuclear-weapon states (NNWS). NWS, such as the United States, Russia, China, France, and the United Kingdom, are all committed to nuclear disarmament while pursuing peaceful uses of nuclear energy. NNWS pledged not to acquire nuclear weapons and to accept International Atomic Energy Agency (IAEA) inspections and safeguards on their nuclear activities.

The IAEA monitors Non-Proliferation Treaty compliance by conducting inspections on states' nuclear programs to ensure they are used for peaceful purposes. Central to this monitoring is the requirement of all states that are party to the NPT to demonstrate transparency, openness, and accountability in their nuclear activities. Countries such as India, Pakistan, Israel, and North Korea own nuclear warheads but are not part of the NPT. These states developed their nuclear weapons programs outside the framework of the NPT. 

Over the years, there have been cases where countries have been suspected or proven to infringe or violate the NPT. For example, North Korea withdrew from the NPT in 2003 and conducted several nuclear tests, resulting in international condemnation. Similarly, Iran's nuclear programmes have also faced international scrutiny and suspicions of potential violations.