Relationship between International Humanitarian Law and International Criminal Law

International Humanitarian Law (IHL) and international criminal law are two interrelated but distinct branches of international law. They have different areas of regulation, but together play an important role in protecting people during armed conflicts and ensuring accountability for the most serious international crimes.

What does International Humanitarian Law regulate?

IHL applies during armed conflicts and aims to reduce human suffering and protect people affected by war. All parties to a conflict are required to comply with its rules.

IHL protects, among others, civilians, the wounded and sick, prisoners of war, medical personnel and other people who are not, or are no longer, taking part in hostilities. It also places restrictions and prohibitions on the means and methods of warfare.

What does international criminal law regulate?

International criminal law defines international crimes and establishes individual criminal responsibility for their commission. The main international crimes are genocide, crimes against humanity, war crimes and the crime of aggression.

Responsibility may arise not only for those who directly commit a crime but, depending on the circumstances, also for ordering, planning, aiding or otherwise participating in its commission.

How are they connected?

International Humanitarian Law and international criminal law intersect most closely in the area of war crimes. Serious violations of IHL may, when all the necessary conditions are met, constitute war crimes and give rise to individual criminal responsibility.

At the same time, not every violation of IHL constitutes a war crime. Likewise, not all international crimes are violations of IHL: genocide and crimes against humanity, for example, have their own legal elements.

IHL establishes the limits of what is permissible during armed conflict, while international criminal law establishes responsibility for the most serious international crimes. Together, they help protect people during war and ensure an appropriate legal response to the most serious violations.