text: Chapter 1
  Martens Clause
  Until a more complete code of the laws of war has been issued, the High Contracting
  Parties deem it expedient to declare that, in cases not included in the Regulations
  adopted by them, the inhabitants and the belligerents remain under the protection and
  the rule of the principles of the law of nations, as they result from the usages
  established among civilized peoples, from the laws of humanity, and the dictates of the
  public conscience.
  Figure 1-2. Martens Clause
  OVERVIEW
  1-19. Three interdependent principles—military necessity, humanity, and honor—provide the foundation for
  other derivative LOAC principles—most importantly, distinction and proportionality—as well as most of the
  treaty and customary rules of LOAC. Paragraphs 1-23 through 1-48 explain the principles of military
  necessity, humanity, honor, distinction, and proportionality. See table 1-1.
  Table 1-1. Application of basic LOAC principles
  +
  Principle Alternate Names Paragraphs Summary
  Military Necessity 1-23 to 1-27 Justifies the use of all measures
  required to defeat the enemy as
  quickly and efficiently as possible that
  are not prohibited by the law of
  armed conflict.
  Humanity Humanitarian Principle; 1-28 to 1-30 Basis of protection for civilians; forbids
  Unnecessary Suffering; inflicting suffering, injury, damage, or
  Superfluous Injury destruction unnecessary to accomplish
  a legitimate military purpose.
  Honor Chivalry 1-31 to 1-33 Demands a certain amount of fairness
  and a certain mutual respect between
  opposing forces.
  Distinction Discrimination 1-34 to 1-43 Distinguishing between combatants
  and military objectives on the one hand
  and civilians and civilian objects on the
  other in offense and defense.
  Proportionality 1-44 to 1-48 Requires commanders to refrain from
  attacks in which the expected loss or
  injury to civilians and damage to
  civilian objects incidental to such
  attacks would be excessive in relation
  to the concrete and direct military
  advantage expected to be gained. It
  also underlies the requirement to take
  feasible precautions to reduce the risk
  of harm to civilians, other protected
  persons and civilian objects.
  1-20. LOAC principles provide the foundation for the specific LOAC rules. These principles, however, are
  not as specific as rules, and thus interpretations of how principles apply to a given situation may vary.
  Nonetheless, understanding LOAC principles helps legal practitioners (1) interpret specific treaty or
  customary rules, (2) apply these rules to novel or complex situations, and (3) understand how LOAC operates
  as a coherent system to regulate the conduct of hostilities. This section therefore illustrates the operation of
  the general principles by briefly discussing some specific rules. For information about applying the specific
  rules, the reader should look to pertinent sections in later chapters that discuss those rules.