Rule 24
The connection between a military objective and military action may be direct or indirect.
[Commentary]
- As set forth in Rule 1 (y), the definition of military objectives depends in part on their making “an effective contribution to military action”. This Rule stresses that the connection between the target and ongoing military operations need not be direct. For instance, it is lawful to attack enemy military storage depots or barracks far from the battlefield because such assets constitute reserves for further military action by the enemy. It is also well-accepted that factories producing munitions and military equipment are lawful targets (see Rule 22 (a)). So too would be a port, railroad, road or airport used in the transport of supplies necessary for the production by the factory of military items (see Rule 23).
- There is a controversy as to whether “war-sustaining” economic objects qualify as military objectives. A war-sustaining economic object is one which indirectly but effectively supports the enemy’s overall war effort.[262] Those who subscribe to the qualification of such objects as military objectives argue that a Belligerent Party’s war-sustaining capability is directly connected to its combat operations. For instance, they contend that a Belligerent Party may lawfully attack export oil production intended for Neutrals since the profits finance the war effort. Materials of actual military value to the enemy — such as oil or petrol dedicated to military use — are not related to the argument, inasmuch as they constitute military objectives by nature. The crux of the issue is related to revenues from exports of oil which is not put to military use by the enemy. The majority of the Group of Experts took the position that the connection between revenues from such exports and military action is too remote. Consequently, it rejected the war-sustaining argument (see also paragraph 8 of the Commentary on Rule 1 (y)).
- The connection between the military objective and “military action” (concept which appears in the definition of military objectives, see Rule 1 (y)) must be actual and discernible, not merely hypothetical or speculative. For instance, the destruction of a civilian airfield incapable of launching military aircraft cannot be justified on the basis that the enemy might one day possess the means of launching and recovering in that airfield. Of course, if the enemy has a clear-cut intent to transform the civilian airfield into one usable for military purposes, the purpose criterion of Rule 22 (c) may turn it into a military objective by purpose.
- Further, the action in question must be military in nature and not, for instance, political, financial, economic or social. As an example, striking otherwise civilian targets in order to create the impression that the enemy civilian leadership is weak would not constitute an attack against a military objective which contributes to the enemy’s military action.
- Second subparagraph of Para. 8.2.5 of NWP (“Objects”): “Proper objects of attack also include enemy lines of communication, rail yards, bridges, rolling stock, barges, lighters, industrial installations producing war-fighting products, and power generation plants. Economic objects of the enemy that indirectly but effectively support and sustain the enemy’s war-fighting capability may also be attacked.”
Categories: E: General Rules

