An indiscriminate attack is a category of unlawful conduct under international humanitarian law (IHL) defined principally in Article 51(4) of Additional Protocol I (1977) to the Geneva Conventions. The provision identifies three types: (a) attacks not directed at a specific military objective; (b) attacks employing a method or means of combat that cannot be directed at a specific military objective; and (c) attacks employing a method or means whose effects cannot be limited as required by the Protocol. In each case, the attack is treated as striking military objectives and civilians or civilian objects without distinction.
Article 51(5) supplements this by treating two further categories as indiscriminate: area bombardment that treats as a single military objective several clearly separated objectives in a city, town, or village containing civilians; and attacks expected to cause civilian harm excessive in relation to the concrete and direct military advantage anticipated — the rule of proportionality.
The prohibition is widely regarded as customary international law, binding even on states that have not ratified Additional Protocol I, as reflected in Rules 11–13 of the ICRC's Customary IHL Study. Violations can constitute war crimes under Article 8 of the Rome Statute of the International Criminal Court when committed intentionally.
Key cases have shaped the doctrine. The ICTY's Prosecutor v. Galić (Trial Judgment, 2003; Appeals Judgment, 2006) convicted the Bosnian Serb general for a campaign of sniping and shelling against civilians in Sarajevo, treating indiscriminate shelling as evidence of attacks on civilians. The ICJ's 1996 Nuclear Weapons Advisory Opinion affirmed distinction and the prohibition on indiscriminate weapons as "intransgressible" principles of humanitarian law.
Common practical examples include:
- Unguided rocket or mortar fire into populated areas
- Use of weapons with wide-area effects in cities
- Cluster munitions or landmines deployed without targeting safeguards
- "Carpet" or area bombardment of mixed civilian-military zones
Determining whether a specific strike was indiscriminate is fact-intensive, turning on weapon choice, intelligence, precautions taken, and the proximity of civilians.
Example
In its 2022 report on the conflict in Ukraine, the UN Independent International Commission of Inquiry documented Russian strikes using unguided munitions in populated areas of Kharkiv and Chernihiv that it characterised as indiscriminate attacks.