Practice Relating to Rule 145. Reprisals
Section C. Proportionality of reprisals
New Zealand’s Military Manual (1992) states:
[The reprisal] must be proportionate to the original wrongdoing … The proportionality is not strict: if the reprisal is to be effective, it will often be greater than the original wrongdoing. Nevertheless, there must be a reasonable relationship between the original wrong and the reprisal measure.
The manual further states:
In order to be considered a reprisal, an act must have certain characteristics: … A reprisal must be proportional to the original violation. Although a reprisal need not conform in kind to the same type of acts complained of (bombardment for bombardment, weapon for weapon) it may not significantly exceed the adverse Party’s violation either in violence or in effect. Effective but disproportionate reprisals cannot be justified by the argument that only an excessive response will forestall further transgressions.