The Essence and Significance of Customary International Humanitarian Law (IHL)

Customary International Humanitarian Law (IHL) refers to a set of legal norms that have evolved through widespread and consistent state practice, accompanied by the belief that such practices are legally obligatory. These norms are not written down in formal treaties but are binding on all states, regardless of whether they have signed specific agreements like the Geneva or Hague Conventions. Customary IHL is derived from general practice accepted as law by states, meaning it arises from the consistent and general actions of states and their belief that these actions are legally required.

Customary norms of IHL are the laws and customs of war that have developed throughout human history. In ancient times, they took the form of ‘military codes’ or certain rules of engagement agreed upon by the belligerents. Although these were typically not enshrined in law, they eventually became generally accepted. For example, the prohibition of attacks on civilians and civilian objects, restrictions on the use of certain types of weapons, and the protected status of medical and religious personnel.

The significance of customary international humanitarian law lies in the fact that it is binding on all states, even those that are not parties to formal international treaties. It also applies to unrecognised states or even non-state entities (armed groups).

Here are some reasons for the exceptional importance of customary IHL:

• Universality of application: Customary IHL applies to all states, regardless of whether they are parties to international humanitarian law treaties.
• Application to under-regulated areas: It applies to areas that are insufficiently regulated by conventions, particularly in non-international armed conflicts.
• Extension to non-state parties: Customary IHL extends to non-state parties to armed conflict, including persuading non-governmental armed groups or unrecognised states to comply with it.

The Ukrainian Red Cross, in fulfilling its mission, continues to promote awareness of international humanitarian law, playing a key role in its implementation at the national level.