Martens Clause
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. 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.