Armed conflict – international humanitarian law

As of 30 September 2026.

International humanitarian law (IHL) regulates the conduct of hostilities and the protection of persons and objects once an armed conflict exists. Its treaties, notably the Geneva Conventions of 1949 and Additional Protocol I of 1977, contain no provisions specific to computer networks. The questions in this subject area concern how distinction, proportionality, precautions, the protection of civilian and specially protected objects, and the legal review of new weapons apply to cyber operations and information activities in armed conflict. The UN Group of Governmental Experts noted in 2021 that IHL applies only in situations of armed conflict. The ICRC and the International Conference of the Red Cross and Red Crescent have addressed the application of IHL to ICT activities.

• “Attack”. Whether a cyber operation that disables but does not physically damage an object is an “attack” under Art. 49 AP I. The ICRC considers that it is; State positions differ.
• Data. Whether civilian data can itself be a protected civilian object is answered differently in national positions.
• Civilian participation. The involvement of civilian “hackers” and private companies raises questions of direct participation in hostilities and of State obligations to restrain them.
• Legitimation. Some States have expressed concern that affirming the applicability of IHL could legitimise cyber warfare; the ICRC states that it does not.
• Shared infrastructure. Protection of cross-border civilian infrastructure, such as undersea cables and satellite networks, and the proposed “digital emblem”.

• Additional Protocol I to the Geneva Conventions (1977) – attacks, civilian objects, weapons review.
• ICJ Advisory Opinion on Nuclear Weapons (1996) – IHL principles apply to all weapons.
• Tallinn Manual 2.0 (2017) – non-binding expert rules.
• National positions on international law in cyberspace – State views on IHL.
• UN and CCW processes on autonomous weapons – IHL and autonomous weapons.
• Rome Statute: crime of aggression – war crimes committed by cyber means.
• Gap: protection of nuclear command, control and communications – nuclear-related systems.

• Use of force, intervention and cyber operations
• Artificial intelligence and autonomous weapons
• International criminal law
• Timeline · Glossary