Diplomat Friedrich Martens from which the clause takes its name.

The Martens Clause (pronounced /mar'tɛnz/) is an early international law concept first introduced into the preamble of the 1899 Hague Convention II – Laws and Customs of War on Land.[1] There are differing interpretations of its significance on modern international law, with some scholars simply treating the clause as a reminder international customary law still applies after a treaty is ratified while others take a more expansive approach where the clause provides that because international treaties cannot be all encompassing, states cannot use that as a justification for an action.

Clause

The clause took its name from a declaration read by Friedrich Martens,[2] the delegate of Russia at the Hague Peace Conferences of 1899.[3] The Clause was introduced as compromise wording for the dispute between the Great Powers who considered francs-tireurs to be unlawful combatants subject to execution on capture and the smaller states who maintained that they should be considered lawful combatants.[4][5] It reads as follows:

The Clause appears in a slightly modified form in the 1907 Hague conventions:

Until a more complete code of the laws of war has been issued, the High Contracting Parties deem it expedient to declare that, in cases not included in the Regulations adopted by them, the inhabitants and the belligerents remain under the protection and the rule of the principles of the law of nations, as they result from the usages established among civilized peoples, from the laws of humanity, and the dictates of the public conscience.

— Laws and Customs of War on Land (Hague IV), 18 October 1907[6][7][9]

The clause did not appear in any of the Geneva Conventions of 1949,[10] but it would be included in the additional protocols of 1977.[11] It is in article 1 paragraph 2 of Protocol I (which covers international conflicts),[12] and the fourth paragraph of the preamble to Protocol II (which covers non-international conflicts).[13] The wording in both is identical but slightly modified from the version used in the Hague Convention of 1907:[14]

Recalling that, in cases not covered by the law in force, the human person remains under the protection of the principles of humanity and the dictates of the public conscience