text: Conduct of Hostilities
  Damage Incidental to Combat Operations Not Prohibited
  The general premise in paragraph 2-135 must be viewed in light of the fact that combat has definite
  adverse effects on the natural environment. Routine conventional military operations involving the
  employment of air, ground, and naval forces that may cause damage to the environment are not activities
  prohibited by LOAC.
  Environmental Modification Convention
  The Convention on the Prohibition of Military or Any Other Hostile Use of Environmental
  Modification Techniques (ENMOD Convention), an arms control agreement, prohibits military or other
  hostile use of environmental modification techniques that have “widespread, long-lasting or severe effects as
  a means of destruction or damage or injury to another State.”
  Environmental modification technique refers to any method of warfare for changing—through
  the deliberate manipulation of natural processes—the dynamics, composition, or structure of the Earth
  (to include its biota, lithosphere, hydrosphere, and atmosphere) or outer space. Examples of
  environmental effects likely to be widespread, long-lasting, or severe could include inducement of a tidal
  wave and seeding of clouds to induce rainfall.
  An action that constitutes an environmental modification technique would only violate the ENMOD
  Convention if the action yielded a level of damage meeting one of three criteria as defined in the ENMOD
  Convention. The ENMOD Convention defines these three criteria as follows:
  * Widespread encompasses an area on the scale of several hundred square kilometers.
  * Long-lasting means lasting for a period of months, or approximately a season.
  * Severe involves serious or significant disruption or harm to human life, natural and economic
  resources, or other assets.
  As is the case with LOAC prohibitions set forth above, conventional military means or methods of
  warfare are not techniques calculated to cause the form of damage prohibited by the ENMOD Convention.
  AP I Provisions on Environmental Protection
  There are two provisions of AP I that specifically address the protection of the environment.
  Article 35(3) of AP I prohibits the employment of means or methods of warfare that are intended , or may be
  expected to cause widespread, long-term and severe damage to the natural environment. Article 55 of AP I
  provides that care shall be taken to protect the natural environment against such widespread, long-term, and
  severe damage and prohibits means and methods of warfare which are intended or expected to cause such
  damage and prejudice the health and survival of the population. Article 55 further prohibits attacks against
  the natural environment by way of reprisal.
  The United States has not accepted these provisions and repeatedly expressed the view that they are
  overly broad and ambiguous and do not constitute customary international law. These provisions fail to
  acknowledge that the use of such weapons is prohibited only if their use would cause incidental injury to the
  civilian population that is clearly excessive in relation to the concrete and direct overall military advantage
  anticipated (see DOD Law of War Manual, 6.10.3.1).
  Post-Conflict Battlefield Clean-Up
  The environmental effects of conventional armed conflict have the potential to last long after the
  conflict’s conclusion, posing ongoing risks to innocent civilians, and the civilian population as a whole, if
  permitted to remain. The primary responsibility for cleaning up the battlefield of the so-called “remnants of
  war” (such as unexploded ordnance) lies with the government that controls the territory in which the remnants
  remain (CCW Protocol V art. 3). Others, such as international organizations and nongovernmental
  organizations, may offer and provide assistance.