States and parties to a conflict have an overarching obligation to “respect and ensure respect” for IHL “in all circumstances”. It is uncontested that preparatory measures must be taken to implement IHL and that its implementation needs to be supervised. This requires states and parties to a conflict, inter alia, to take measures to ensure that the development and use of means and methods of warfare fully comply with IHL, and to prevent outcomes that would be unlawful.
This is also applicable to cyberspace and the cyber means and methods of warfare. As with any other weapon, means or method of warfare, States have the positive obligation to determine, in their study, development, acquisition or adoption, whether their employment would, in some or all circumstances, violate existing international law. In this regard, the obligation to assess the legality of a new weapon as set out in Art. 36 of Additional Protocol I to the Geneva Conventions is an important element to prevent or restrict the development and employment of new cyber weapons that would fail to meet in particular the obligations set out above.
Switzerland’s Position Paper on the Application of International Law in Cyberspace (27 May 2021) 10-11
Official compendium of voluntary national contributions on the subject of how international law applies to the use of information and communications technologies by States submitted by participating governmental experts in the Group of Governmental Experts on Advancing Responsible State Behaviour in Cyberspace in the Context of International Security established pursuant to General Assembly resolution 73/266 (13 July 2021) A/76/136, 95
