Related Rule
Solomon Islands
Practice Relating to Rule 140. The Principle of Reciprocity
In its written statement submitted to the ICJ in the Nuclear Weapons (WHO) case in 1994, Solomon Islands stated:
The rule elaborated in Art. 1 [common to the 1949 Geneva Conventions] also indicates that reciprocity has no place in the law of armed conflicts … The principle of non-reciprocity excludes a fortiori recourse to reprisals in relation to the use of nuclear weapons, even against combatants. 
Solomon Islands, Written statement submitted to the ICJ, Nuclear Weapons (WHO) case, 9 June 1994, § 3.78.