Practice Relating to Rule 8. Definition of Military Objectives
Section G. Economic installations
New Zealand’s Military Manual (1992) states that “energy installations [and] war supporting industries are examples of objects universally regarded as military objectives”.
The manual further states:
Industrial installations producing materiel for combat forces, fuel dumps and distribution centres supplying military users, and industrial installations that repair and replenish lines of communication (such as conventional power plants and vehicle plants), and other economic targets may be attacked if they meet the criteria for military objectives.
In general, the manual considers that:
Economic targets that indirectly but effectively support enemy operations may also be attacked to gain a definite military advantage. For example, an 1870 international arbitral tribunal recognized that the destruction of cotton was justified during the American Civil War since the sale of cotton provided funds for almost all Confederate arms and ammunition. Authorization to attack such targets will be reserved to higher authority.