ICRC databases on international humanitarian law
Treaties and Documents
1949 Conventions and Additional Protocols, and their Commentaries
Historical Treaties and Documents
San Remo Manual on International Law Applicable to Armed Conflicts at Sea, 12 June 1994
ARMED CONFLICTS AND THE LAW OF SELF-DEFENCE
SECTION II : ARMED CONFLICTS AND THE LAW OF SELF-DEFENCE
3. The exercise of the right of individual or collective self-defence recognized in Article 51 of the Charter of the United Nations is subject to the conditions and limitations laid down in the Charter, and arising from general international law, including in particular the principles of necessity and proportionality.
4. The principles of necessity and proportionality apply equally to armed conflict at sea and require that the conduct of hostilities by a State should not exceed the degree and kind of force, not otherwise prohibited by the law of armed conflict, required to repel an armed attack against it and to restore its security.
5. How far a State is justified in its military actions against the enemy will depend upon the intensity and scale of the armed attack for which the enemy is responsible and the gravity of the threat posed.
6. The rules set out in this document and any other rules of international humanitarian law shall apply equally to all parties to the conflict. The equal application of these rules to all parties to the conflict shall not be affected by the international responsibility that may have been incurred by any of them for the outbreak of the conflict.