States have a primary responsibility under international humanitarian law to protect civilians from the effects of armed conflict, to provide medical assistance to wounded soldiers, and to ensure the humane treatment of prisoners of war.

States can enforce international humanitarian law by adopting national laws that implement the provisions of international humanitarian law, by establishing national courts or tribunals to prosecute violations of international humanitarian law, and by cooperating with other states to investigate and prosecute violations of international humanitarian law.

The ICRC has a mandate to monitor compliance with international humanitarian law, to provide humanitarian assistance to victims of armed conflict, and to promote the development of international humanitarian law.

The UN Security Council has the power to authorize the use of force to protect civilians from the effects of armed conflict, to impose sanctions on states that violate international humanitarian law, and to establish international criminal tribunals to prosecute violations of international humanitarian law.

Some of the challenges to enforcing international humanitarian law include the lack of a universal definition of war crimes, the difficulty of gathering evidence of violations of international humanitarian law, and the unwillingness of states to prosecute their own nationals for violations of international humanitarian law.