Under the SRUF, when might a military action be considered unlawful?

A military action may be considered unlawful under the Standing Rules for the Use of Force (SRUF) if the force used is deemed unnecessary or excessive. This principle is rooted in the notion that military force should be proportional to the threat faced and necessary to achieve military objectives. The assessment of necessity and proportionality is critical in determining the legality of an action. If an action exceeds this threshold—meaning that the level of force used is not justified by the situation at hand or is out of proportion to the military advantage anticipated—it may violate international laws and rules governing armed conflict.

The other choices provide scenarios that do not directly pertain to the legal framework established by the SRUF for determining the lawfulness of military action. For example, long-term engagements may have specific rules governing them but do not inherently make an action unlawful. Delays in communication from headquarters can complicate situations but do not by themselves render military actions illegal. Similarly, public opinion can influence perceptions and policy but does not determine the legality of military actions according to SRUF guidelines.