The Vietnam War had a major and long-lasting impact on the environment of the countries affected. The environment of Vietnam was severely degraded by the use of defoliants, bombing and other military activities.[1] North Vietnam utilized the geography and ecology of the region to conceal their activities and move resources, such as via the complex network of tunnels and paths in the Ho Chi Minh trail. In response, the United States developed and deployed technologies and campaigns to clear forests and destabilize soil, greatly impacting the environment.[2] Over time, the long-term agricultural productivity in parts of Vietnam was reduced by many herbicidal agents and bombing campaigns.[3] The war has also been linked to extensive deforestation and influenced the hydrology of the Mekong region.[4][5]