Down Is Not Always Out: Hors De Combat in the Close Fight

by | Jul 8, 2021

hors de combat. MET 2018. Davide Dalla Massara

Note: this piece builds on a recent article published in Infantry Magazine. While that article was intended “to equip infantry leaders with the knowledge required to train their soldiers to make confident, split-second decisions in combat,” this piece is focused on the legal nuances and tensions surrounding U.S. policy on persons hors de combat.

The advent of new technology such as unmanned, strike-capable aircraft has spawned scholarship and commentary on persons hors de combat (see here, here, and here). Less, however, has been written about persons hors de combat from wounds in the context of ground combat (there are notable exceptions, many of them centered around an entirely fictional fact patten involving a senior enlisted leader and a shovel). Under the law of armed conflict (LOAC), persons wounded and persons hors de combat are related, but not coextensive categories. Hors de combat from wounds confers legal protection from attack, while merely being wounded does not provide that protection. Once an attacker makes a good faith determination that an enemy is a lawful object of attack that enemy remains a lawful target, even when he is wounded, until the attacker is reasonably certain the individual is hors de combat.

The Principle of Distinction

The American military strives to comply with the law of war during all armed conflicts and (absent rare and unfortunate aberrations) carries out all military operations consistent with the law of war’s fundamental principles and rules. These include the principles of military necessity, humanity, distinction, proportionality, and honor. The law of war principle of distinction, sometimes called discrimination, requires parties to a conflict to distinguish lawful targets from civilians and persons protected from attack. Under the law of war soldiers do not need to wait for an enemy to exhibit hostile intent or commit a hostile act when conducting status-based targeting—they may attack and kill enemy troops or fighters on sight provided other LOAC principles such as proportionality are satisfied. This privilege has been abridged and curtailed by theater policy or rules of engagement (ROE) during recent stability operations and counterinsurgency campaigns. However, under the baseline law of war rules enemy troops are lawful targets because of their status as members of an armed force or organized armed group. They may be attacked consistent with LOAC rules unless their status changes to grant them protection.

Enemy troops are protected from attack if they are rendered hors de combat due to wounds, surrender, or capture. A person who is out of combat is protected from further attack, even if they are a member of enemy armed forces. In addition to distinction, the principles of military necessity and humanity also prohibit engaging enemies who are out of the fight, as attacking them serves no valid military purpose and their suffering would therefore be unnecessary.

Hors de Combat

Protection for persons hors de combat is a bedrock concept of LOAC. U.S. Army doctrine, including infantry manuals specifically identifies “wounded personnel who are out of combat” as no longer being lawful targets, and leaders must train their soldiers not to engage enemies once those enemies are hors de combat. This protection applies to all enemies once they are out of the battle, from uniformed enemy soldiers to terrorist fighters or other unprivileged belligerents.

However, not all wounded personnel are automatically out of combat. The United States recognizes as customary international law a three factor test for an individual to be considered out of combat due to wounds: 1) he must be wounded; 2) the wound must make him incapable of defending himself; and 3) he must abstain from any hostile act and may not attempt to escape. Under international law, the standard for determining whether a target is out of the fight is whether, given the information available to the attacker in the moment, the target “should be recognized by a reasonable [person] as being hors de combat.” This standard is one of “common sense and good faith,” often expressed as “reasonable certainty” in contemporary U.S. military targeting parlance.

When is an Enemy Out of the Fight?

An enemy who is out of the fight is protected and cannot be attacked or reengaged. Whether an enemy is out of the fight, however, is not always immediately obvious. The International Committee for the Red Cross (ICRC) finds uncontroversial the notion that wounded and hors de combat are not the same. They acknowledge that individuals can be “wounded or sick, whether severely or not, but … not (yet) incapacitated by their medical condition.” Wounded combatants can continue to fight, and contemporary adversaries have engaged in tactics such as “playing dead” or other forms of perfidy.

Standing alone, the fact that an enemy is laying still on the ground is insufficient to determine that target has fallen out of the fight. Also, the mere appearance of visible wounds is probably not enough, unless the nature of those wounds makes it clear the person is unable to defend themselves or unable to continue to fight. Clear indicators of hors de combat from wounds include decapitation or an amount of pooling blood that makes it plain and obvious the enemy’s injuries were mortal. If an attacker is not convinced an enemy is out of the fight, that enemy continues to be a lawful target and can be attacked or reengaged. However, the practice of automatic, indiscriminate attacks on downed enemies to include a technique or standard procedure of firing “security rounds,” “double-taps,” or “death checks,” is unlawful. The possibility of a theoretical threat from general enemies is insufficient—the determining factor is a good faith belief that a specific enemy, though wounded, is not yet out of the fight. Unless a reasonable attacker would be convinced a wounded enemy is out of the fight (or the wounded enemy is clearly, genuinely, and unconditionally surrendering under circumstances when it would be feasible to accept that surrender) the law presumes that the enemy remains a lawful target.

Proportionality and Protections for Enemy Hors De Combat

The United States does not consider hors de combat enemies as civilians for proportionality purposes because their proximity to lawful military objectives constitutes some degree of assumption of risk. This interpretation of international law is far from universal, and this is a good example of an issue where scholars and multinational partners may differ in opinion and practice. Australia, for example, requires “soldiers who are ‘out of combat’ and civilians … to be treated in the same manner” for proportionality purposes.

The United States also takes the position (not without controversy) that the presence of an hors de combat enemy does not furnish a “protective bubble” or “legal fortress” for other enemies who remain in the fight. Hors de combat enemies are not treated as civilians in a proportionality analysis. So, while the hors de combat individuals may not themselves be the direct targets of attacks, incidental harm to them need not be balanced against the direct and concrete military advantage gained by continuing to engage their comrades (Michael Schmitt recently noted a similar point about proportionality and “dual-use” structures). This means an attacker can engage the remaining enemies so long as their target is not the individual who is out of the fight, even if that attack will result in foreseeable incidental harm to that individual hors de combat. They still must, however, take feasible precautions to reduce harm to the enemy who is out of combat.

The U.S. acknowledges that combatants must take feasible precautions in planning and conducting attacks to reduce the risk of harm not only to civilians but also “to other persons and objects protected from being made the object of attack.” The American position sees the requirement to take feasible precautions in launching attacks as distinct from the principle of proportionality’s prohibition on attacks that cause excessive incidental harm. Both obligations are, however, “mutually reinforcing.” In other words, feasible precautions does not mean weapon effects are not permitted to impact the enemy out of the fight, just that the enemy who is out of the fight may not be targeted for direct attack and that the attacker must use practicable precautions to avoid effects on him. The DoD Law of War Manual is confusing on this point. It discusses feasible precautions as a subset of proportionality (see sec 5.11) while excluding enemy hors de combat from the proportionality rule (see sec 5.10.1). And, yet it still imposes the requirement to take feasible precautions to spare enemy wounded (not just those hors de combat!) from incidental harm (but maybe only during non-international conflict, see sec The best reading of the American view is that hors de combat enemies do not transform into civilians for proportionality purposes, but instead comprise a “situation-specific standard where an enemy combatant is protected by the law from direct attack.”

For example, imagine soldiers attack an enemy bunker and shoot an enemy who falls inside the bunker. The soldiers are convinced that particular enemy fighter is out of combat, but other enemy fighters continue to engage the soldiers from the same bunker. The soldiers could employ direct fire, fragmentation grenades, a recoilless rifle, or even close air support to silence the bunker, as the target of their attack is the enemy fighters who remain in the fight and the attack satisfies the principle of distinction—the bunker and the unharmed fighters inside of it are lawful targets and the hors de combat enemy is not treated as a civilian, thus rendering him “off the books” for proportionality purposes. The soldiers must still take feasible precautions, such as employing direct fire or other systems that would minimize effects on the hors de combat individual if reasonable given the tactical situation, but the presence of the enemy hors de combat will not prohibit attack on the other fighters in the bunker on proportionality grounds. The mere presence of enemies out of the fight never prevents an attacker from finishing that fight against remaining enemy.


The protections for individuals rendered hors de combat by wounds are fundamental to the law of war. The application of those protections to the close fight, however, is frequently dismissed as axiomatic or so common-sense that it is not worth discussing. The unsettled (and arguably muddled) legal landscape surrounding the interplay between discrimination, proportionality, and feasible precautions as applied to persons hors de combat suggests this is an area of the law that warrants additional inquiry. Practitioners’ tendency to ignore the nuances of the law surrounding enemies out of the fight due to wounds results in a lack of training and the proliferation of urban legends and unlawful techniques.

LOAC differentiates between persons wounded and persons hors de combat, and legal advisors must be able to train operators to apply the correct legal standard, including the presumption that a lawful object of attack remains a lawful object of attack until the attacker is reasonably certain the target is destroyed or hors de combat.


Major Matt Montazzoli is an active duty Army judge advocate, currently assigned as Operational Law Attorney (Military Personnel Exchange Program), 1st Division / Deployable Joint Force Headquarters, Australian Army at Gallipoli Barracks, Brisbane.