To verify compliance with the two rules listed above [ie, prohibition of indiscriminate weapons and weapons that cause unnecessary suffering], a State intent on fielding a new weapon must conduct a thorough legal review. This requirement for a legal review, which appears in Article 36 of Additional Protocol I, ensures that the weapon is not indiscriminate and that it would not cause unnecessary suffering or superfluous injury. The review also determines whether there is any other particular provision under the law of armed conflict which would prohibit the use of the weapon. Customary law requires this legal review of weapons and weapon systems (referred to as the “means of warfare”), and these reviews are thereby required by all States, including those not party to the Protocol. Furthermore, if a weapon system is significantly modified after its initial fielding, an additional review would then be necessary. The development of any fully autonomous weapon system would clearly require such legal reviews.
Statement on Legal Aspects by Ambassador Michael Biontino (14 May 2014)
