The term military objective is often used to describe the overall plan of a given mission: to take a certain hill, to reach a river, or to bring back hostages. In the more narrow sense, a military objective can refer to a specific target for neutralization or destruction. The laws of war use the term in the latter sense: to identify and attack a locality, facility, or enemy personnel that under the circumstances constitutes a legitimate military target. Certain potential objects or individuals clearly are unlawful targets. For example, any direct attack upon the civilian population, or upon any places, localities, or objects used solely for humanitarian, cultural, or religious purposes such as hospitals, churches, mosques, schools, or museums are immune. On the other hand, such immunity is lost if they are used or employed for enemy military purposes. There is always a presumption in favor of the immunity. Additional Protocol I to the Geneva Conventions of 1949 provides “in case of doubt whether an object which is normally dedicated to civilian purposes, such as a place of worship, a house or other dwelling or a school, is being used to make an effective contribution to military action, it shall be presumed not to be so used.”

At one time, over a century ago, the laws of war set forth a simple rule as to what constituted a military objective. It was a fort or fortified place and adjacent towns assisting in their defense. This definition soon became obsolete at the beginning of the twentieth century as firepower increased the range of destruction and aircraft became an instrument of war that penetrated deep into enemy territory. The concept of the “defended place” was substituted for forts and fortified places at the two Hague Peace Conferences, which codified the laws of armed warfare just prior to World War I. Of course, what constituted a defended place was far more indefinite and variable than what qualified as a fort or fortress. The average person can identify a fort, but when is a town or city defended? Is it defended if it contains no military installations or armed forces and has no strategic military value but remains within the protective zone of an air defense unit which covers hundreds of miles of territory? The term defended place became as outmoded as the so-called fortified place with the advent of World War II and the increased capabilities of aerial and artillery firepower to attack the industrial infrastructure of war.

There was an intergovernmental attempt after World War I to specify what constituted legitimate military objectives by enumerating categories of legitimate targets. The rules proved too restrictive and no belligerent nation cited them as precedent in subsequent conflict. It became easier to list those categories of personnel and places that were not legitimate objects of attack than to define those that were. However, the wholesale destruction and killing wrought by mass aerial bombing in World War II made it imperative to redefine the scope of the military objective. The systematic destruction of urban areas city block by city block and the attack on the morale of the enemy population, which was sanctioned by both Allied and Axis bomber forces, brought forth many outcries for more humane rules of armed conflict. The destruction of the city of Dresden, killing as many as 100,000 civilians in one coordinated attack by British and U.S. bombers in two days in February 1945 reflected the lack of any meaningful definition of the military objective. In the Far East, firebomb attacks alone in the space of a few months killed eighty-four thousand civilians and destroyed many homes and urban facilities. This was before the holocaust of the atom bomb. While these events occurred in a high-intensity, global conflict they demonstrated the urgent need to update and codify the laws of armed conflict and clearly state what could and could not be a legitimate target for hostile attack.

The contemporary rule defining military objects is found in the Additional Protocol I of 1977. Article 52 limits attacks to places, localities, facilities, structures, and “objects which . . . make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.” However, the rules provide specific immunity for certain individuals and localities. First, the civilian population must never be the object of attack, making it clear that morale or terror-bombing tactics are clearly a war crime today. Civilian objects used for peaceful purposes, are also protected. But the new rules go further by providing that in cases of doubt whether certain objects normally used for civilian purposes are being used to help the military mission, thereby losing their protection from attack, a presumption shall be made that it is not so used. Second, Protocol I also outlaws carpet or area bombing tactics. It provides that it is unlawful to bomb “as a single military objective a number of clearly separated and distinct military objectives located in a city, town, village, or other area containing a similar concentration of civilians or civilian objects.” This is a useful and humane rule that eliminates the territorial or mass-bombing attacks so frequently resorted to in World War II, and to a lesser degree in the Vietnam conflict.

The enormous fire-raising attacks by U.S. forces over large urban areas in Japan in 1945 and the devastation wreaked city by city in Europe throughout World War II would be regarded today as flagrant violations of the modern rules and clearly prohibited by the Additional Protocols regardless of the nature or intensity of the conflict. Many contemporary writers of the laws of war consider that the size and scope of the conflict affect the scope of the military objective—that is, as nations devote more of their resources to the war effort and become more heavily committed to a successful conclusion, economic activities such as transportation, supply, and communications normally used only for civilian purposes may become legitimate targets. This is true but still would never today justify expansion of the legitimate target to include the civilian population or civilian areas as such.

Third, Protocol I also provides that any loss of civilian life incidental to the attack on legitimate military targets must be reduced to what is absolutely necessary to accomplish the mission. It would be indiscriminate and unlawful to cause civilian casualties that are excessive under the circumstances. The military target itself always must be identified and individually singled out for attack within the limits of available technology and weapons. Precision guided munitions (PGMs) were used in successful Vietnam air campaigns, such as Linebacker I and II, and made a critical impact on the United States’s successful prosecution in Operation Desert Storm. Where there is a high concentration of civilians, it is imperative to use PGMs, as opposed to “dumb bombs,” when available and subject to military necessity.

Military operations in the Gulf War in 1991 demonstrated the precision with which military targets could be hit without injury or disruption of the civilian population. Tomahawk cruise missiles disabled power plants and missile sites and destroyed military headquarters in Baghdad with minimum loss to civilians and civilian structures. F-117 stealth fighters and F-111 fighter- bombers were able to “thread” laser land-guided bombs through areas as small as doorways and air vents with surgical accuracy. The introduction of PGMs and high technology systems for spotting targets make it even more necessary to isolate the target from the civilian population and dwellings. One air force writer has pointed out that while it would often take forty-five hundred sorties dropping nine thousand gravity bombs (presumably weighing about two thousand pounds each) to destroy a target in 1940–1945, one F-117 on one sortie could take out a precision target with the use of a PGM in the Gulf War. The circular error probable (CEP) or range of the possible hit is now measured in feet, rather than in miles.

Of course PGMs are expensive, not always available for certain missions even to the technologically superior force, and often should be conserved for a later phase of the battle. However the operational decisions on their use cannot obscure the fact that state-of-the-art military combat has forever changed what and how much civilian loss is permissible. An operational decision to use gravity-driven weapons when more precise munitions are available can make the attack excessive and unlawful if civilians are killed who would have been spared with the use of more accurate weapons.

Therefore, the loss of civilians, even deliberately located in and around a military target must clearly be shown to be absolutely necessary. Additional Protocol I specifically stipulates that feasible precautions in minimizing civilian loss includes the choice of weapons as well as the means and methods of attack. For example, bombing a military headquarters facility in a densely populated city would never justify the use of unguided bombs if PGMs were available to the striking force and if it appears that innocent civilians within the vicinity would be injured or killed. However, the defending force cannot deliberately use civilians as a shield for their own military operations, such as moving them into a critical command and control center. An example of this principle is Iraq’s use of the Amirya bomb shelter during the Gulf War. The United States attacked it, killing between two hundred and four hundred civilians, causing some to allege a violation of the laws of war. The fact that civilians are used as a shield does not cause them to lose their normal protection. This means that the attacking forces should nonetheless make particular efforts to avoid or at least minimize their injury or death.

In armed conflicts between two States where only one armed force has high-technology weapons systems the humanitarian rules do not change. Each force is judged by the capabilities it possesses to defend itself or launch an attack. The high technology State cannot rely on the lack of PGMs by its enemy to justify its own resort to less than its own state-of-the-art weaponry. At the same time, the defending force must use all means available to avoid attacks on, or excessive incidental damage to, the civilians when it launches its own defense or attack.

The military commander planning or executing the attack cannot be the final arbiter of whether the loss of civilian life and property is reasonably proportionate to the attacks military advantage. Only by the independent assessment of nonparticipating entities or organizations can the strict rules for the limitation of unnecessary suffering and destruction be upheld.

In the final analysis, the loss of any civilian life or property as a result of an armed attack, regardless of the level of the war, or the intensity of the particular planned mission, must clearly be shown to have been unavoidable with the use of the most precise weapons available to the attacking force.

(See proportionality; military necessity.)