United States of America
Practice Relating to the Use of Prohibited Weapons
The US Field Manual (1956) provides: “In addition to the ‘grave breaches’ of the Geneva Conventions of 1949, the following acts are representative of violations of the law of war (‘war crimes’): … making use of … forbidden arms or ammunition.”
The US Instructor’s Guide (1985) provides that “in addition to the grave breaches of the Geneva Conventions, the following acts are further examples of war crimes: using … forbidden arms or ammunition”.
The US Naval Handbook (1995) states: “The following acts are representative war crimes: … employing forbidden arms or ammunition.”
The US Naval Handbook (2007) states that “[e]mploying forbidden arms or ammunition” is an example of an act that could be considered a war crime.