Rule 36. Directing an attack against a demilitarized zone agreed upon between the parties to the conflict is prohibited.
Volume II, Chapter 11, Section B.
State practice establishes this rule as a norm of customary international law applicable in both international and non-international armed conflicts.
Making a demilitarized zone the object of attack is a grave breach of Additional Protocol I.
A demilitarized zone is generally understood to be an area, agreed upon between the parties to the conflict, which cannot be occupied or used for military purposes by any party to the conflict. Such a zone can be established in time of peace as well as in time of armed conflict. Article 60(3) of Additional Protocol I provides a blueprint for the terms of an agreement on a demilitarized zone, but any such agreement can be tailored to each specific situation, as Article 60 recognizes.
The protection afforded to a demilitarized zone ceases if one of the parties commits a material breach of the agreement establishing the zone.
Practice indicates that international supervision is seen as an appropriate method of verifying that the conditions agreed upon are respected.
The agreement may authorize the presence of peacekeeping forces or police personnel for the sole purpose of maintaining law and order without the zone losing its demilitarized character.
Numerous military manuals provide for the establishment of demilitarized zones and prohibit their attack.
Attacks against demilitarized zones are an offence under the legislation of many States.
Demilitarized zones have been set up in both international and non-international armed conflicts, for example, in the conflicts between India and Pakistan, North and South Korea, Israel and Syria, Israel and Egypt and Iraq and Kuwait, and the conflicts in Bosnia and Herzegovina, Colombia and Nicaragua.
Alleged violations of the status of a demilitarized zone have generally been condemned.