The Vietnam War (1955–1975) is one of the most striking cases of the use of chemical weapons. Defoliant chemicals used by the U.S. Army as part of “Ranch Hand” and “Trail Dust” operations aimed at destroying militarily significant jungle vegetation have led not only to damage and pollution of the area, but also to long-term effects on the health of the local population. In addition to environmental warfare, to destroy vegetation, U.S. troops have also used dangerous toxic substances to directly combat opponents. This article will examine the environmental consequences of the ecological war in Vietnam and the historical and political context of the development of this situation, without which it would be impossible to fully consider this case from the ecological safety and security point of view.