The body of treaties, customs, and practices governing the environmental consequences of armed conflict is a dynamic and rapidly growing area of international law. Until relatively recently, relevant legal provisions were vague, not directly mentioning the environment. In response to US actions in the Vietnam War, however, the international community adopted the 1976 Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques (ENMOD) and the 1977 Additional Protocols I and II to the Geneva Conventions of 1949.
In addition to the environment-specific provisions of these treaties, authors in this section highlight legal constraints found in a variety of other treaties and international custom protecting property, civilian objects, and cultural heritage, which can provide protection without even mentioning the word “environment.” The different provisions can be divided generally into those that govern targeting choices and those that govern weapons choices; both kinds of regimes can be useful for addressing different aspects of wartime environmental protection. In addition, human rights treaties, arms control agreements, customary international law, and domestic and international peacetime environmental norms also prove useful when considering how to prevent and redress wartime environmental harm.
While this section emphasizes those norms applicable to international armed conflict, there also is a need to consider military operations other than war, which include peacetime training operations, as well as police actions or other activities that do not rise to the level of formally declared war.