Types of armed conflict

International humanitarian law specifically exists to govern and regulate conduct in armed conflict. So, it is important to understand what armed conflict is in order to determine where and when IHL will apply.

There are two types of armed conflict under the Geneva Conventions and their Additional Protocols:

1. International armed conflict, occurring between two or more States – this includes belligerent occupation; and
2. Non-international armed conflict, occurring between a State and non-State armed group(s), or between only non-State armed groups. These are often referred to as civil wars.

That said, there are some aspects of IHL that continue to apply in peacetime, extending protections beyond the physical battlespace or at the end of an armed conflict. For example, IHL remains applicable in territories under military occupation, even after the fighting ceases. There are also specific weapons treaties that prohibit not only the use of certain weapons, but also the development, stockpiling, production and sale of those weapons by States.

International armed conflict

International armed conflict (IAC) is the traditional form of warfare that is typically waged between two or more States, for example World War I and World War II. The laws applicable to IAC are primarily found in the Hague Regulations of 1907, the 1949 Geneva Conventions and Additional Protocol I.

Common Article 2 of the Geneva Conventions states,

… the present Convention shall apply to all cases of declared war or of any other armed conflict which may arise between two or more of the High Contracting Parties, even if the state of war is not recognized by one of them.

The Convention shall also apply to all cases of partial or total occupation of the territory of a High Contracting Party, even if the said occupation meets with no armed resistance.

‘conflicts in which peoples are fighting against colonial domination and alien occupation and against racist regimes in the exercise of their right of self-determination…’.

Non-international armed conflict

‘conflicts which take place in the territory of a High Contracting Party between its armed forces and dissident armed forces or other organized armed groups which, under responsible command, exercise such control over a part of its territory as to enable them to carry out sustained and concerted military operations…’.

In summary:

• IHL is the specialist body of law that governs armed conflict. Once an armed conflict exists, IHL will apply to any activity related to that conflict.
• An armed conflict exists whenever there is a use of armed force or belligerent occupation between States (IAC), or when protracted armed violence takes place between States and organised armed groups or between such groups (NIAC).
• Belligerent occupation is the invasion and establishment of control by one State over all or part of the territory of another. This situation is governed by the laws that apply to IAC.