AFDD 2-1.9, page 99

89 Military Necessity. Is this target a valid “military objective”? “Military necessity” acknowledges that attacks can be made against targets, but only targets that are valid “military objectives.” In this case, the term “military objective” in this context comes from the description in the Additional Protocol to the Geneva Convention that describes military objectives as “…(T)hose objects by their nature, location, purpose or use make an effective contribution to military action…” Though the US is not a signatory to the Additional Protocol it views this definition as an accurate restatement of customary international law that we recognize and with which we comply. NOTE: The word “objective” as used above should not be confused with the way “objective” is defined in the DOD Dictionary of Military Terms (“1. The clearly defined, decisive, and attainable goals towards which every military operation should be directed.”) For example, a residential home does not usually make an effective contribution to military action so is not usually a valid military target. However, there are instances and circumstances when something like a residence is a valid military target if an adversary is using it for military purposes (such as a military command post, a fighting position, etc.). In that case, the purpose or nature of the objective has been changed by the adversary’s actions. Unnecessary Suffering (Humanity). Will the use of a particular weapon used to strike a target cause unnecessary suffering? This principle is based in the Hague Conventions restrictions against using arms, projectiles, or materials calculated to cause unnecessary suffering. All conventional weapons in the US inventory are permissible for use unless otherwise restricted by higher authority for operational reasons. These weapons have been reviewed to determine if they comply with the LOAC and have been determined not to cause unnecessary suffering when used in the manner in which they were designed. However, this principle also prohibits using an otherwise lawful weapon in a manner that causes unnecessary suffering. An example of causing unnecessary suffering would be to modify munitions to disperse glass projectiles to complicate providing medical treatment to the wounded. The bottom line is to use weapons and munitions as they are designed. Proportionality. Does the military advantage to be gained from striking a target outweigh the anticipated incidental civilian loss of life and property if this target is struck? This requires the anticipated loss of civilian life and damage to civilian property incidental to attack is not excessive in relation to the concrete and direct military advantage expected from striking the target. Planners and commanders must weigh the expected military advantages to be gained from affecting a target (kinetic or non- kinetic) against the incidental loss or injury to civilians and the damage or destruction of civilian property. The “military advantage anticipated” refers to the advantage anticipated from those actions considered as a whole, and not only from isolated or particular actions. A “military advantage” is not just a tactical gain, but can span the spectrum of tactical, operational, or strategic.