Chile
Practice Relating to Rule 70. Weapons of a Nature to Cause Superfluous Injury or Unnecessary Suffering
In 1991, in a legal report concerning the withdrawal of its reservation to the 1925 Geneva Gas Protocol, Chile stated:
The prohibition of the use of arms, projectiles or material calculated to cause unnecessary suffering … is considered to be a norm of international customary law and hence to be binding on all States, whether or not they are party to the relevant Convention.