The natural environment has been a strategic element of war since the first rock was thrown by the first cave dweller. The armies of ancient Rome and Assyria, to ensure the total capitulation of their enemies, reportedly sowed salt into the cropland of their foes, making the soil useless for farming-an early use of military herbicide, and one of the most devastating environmental effects of war.
But history also provides lessons in eco-sensitive warfare. The Bible, in Deuteronomy 20:19, stays the hand of the warrior to minimize war's impact on nature and men alike:
"When you besiege a city a long time, to make war against it in order to capture it, you shall not destroy its trees by swinging an axe against them; for you may eat from them, and you shall not cut them down. For is the tree of the field a man, that it should be besieged by you?"
War and the Environment: We've Been Lucky so Far
War is waged differently today, of course, and has widespread environmental impacts that last far longer. "The technology has changed, and the potential effects of the technology are very different," says Carl Bruch, co-director of international programs at the Environmental Law Institute in Washington, D.C.
Bruch, who is also the co-author of "The Environmental Consequences of War: Legal, Economic, and Scientific Perspectives," notes that modern chemical, biological, and nuclear warfare has the potential to wreak unprecedented environmental havoc that, fortunately, we haven't seen-yet. "This is a great threat," Bruch says.
But in some cases, precision weapons and other technological advances can shield the environment by targeting key facilities, leaving other areas relatively unscathed. "You could make the argument that these weapons have the ability to minimize collateral damage," says Geoffrey Dabelko, director of the Environmental Change and Security Program at the Woodrow Wilson Center for Scholars in Washington, D.C.
It's Local: the Impact of War Today
Warfare today also occurs infrequently between independent nations; more often, armed conflict breaks out between rival factions within a nation. These localized civil wars, according to Bruch, are usually beyond the reach of international treaties and bodies of law. "Internal conflict is viewed as a matter of sovereignty-an internal matter," he says. As a result, environmental damage, like human rights violations, occurs unchecked by outside organizations.
Though skirmishes, armed conflicts, and open warfare vary tremendously by region and by weapons used, the effects of war on the environment usually involve the following broad categories.
Habitat Destruction and Refugees
Perhaps the most famous example of habitat devastation occurred during the Vietnam War when U.S. forces sprayed herbicides like Agent Orange on the forests and mangrove swamps that provided cover to guerrilla soldiers. An estimated 20 million gallons of herbicide were used, decimating about 4.5 million acres in the countryside. Some regions are not expected to recover for several decades.
Additionally, when warfare causes the mass movement of people, the resulting impacts on the environment can be catastrophic. Widespread deforestation, unchecked hunting, soil erosion, and contamination of land and water by human waste occur when thousands of humans are forced to settle in a new area. During the Rwandan conflict in 1994, much of that country's Akagera National Park was opened to refugees; as a result, local populations of animals like the roan antelope and the eland became extinct.
Military ships, cargo airplanes, and trucks often carry more than soldiers and munitions; non-native plants and animals can also ride along, invading new areas and wiping out native species in the process. Laysan Island in the Pacific Ocean was once home to a number of rare plants and animals, but troop movements during and after World War II introduced rats that nearly wiped out the Laysan finch and the Laysan rail, as well as bringing in sandbur, an invasive plant that crowds out the native bunchgrass that local birds depend on for habitat.
Among the first and most vulnerable targets of attack in a military campaign are the enemy's roads, bridges, utilities, and other infrastructure. While these don't form part of the natural environment, the destruction of wastewater treatment plants, for example, severely degrades regional water quality. During the 1990s fighting in Croatia, chemical manufacturing plants were bombed; because treatment facilities for chemical spills weren't functioning, toxins flowed downstream unchecked until the conflict ended.
Even in regions not directly affected by warfare, increased production in manufacturing, agriculture and other industries that support a war effort can wreak havoc on the natural environment. During World War I, former wilderness areas of the United States came under cultivation for wheat, cotton, and other crops, while vast stands of timber were clear-cut to meet wartime demand for wood products. Timber in Liberia, oil in Sudan, and diamonds in Sierra Leone are all exploited by military factions. "These provide a revenue stream that is used to buy weapons," says Bruch.
Scorched Earth Practices, Hunting, and Poaching
The destruction of your own homeland is a time-honored, albeit tragic, wartime custom. The term "scorched earth" originally applied to the burning of crops and buildings that might feed and shelter the enemy, but it's now applied to any environmentally destructive strategy. To thwart invading Japanese troops during the Second Sino-Japanese War (1937-1945), Chinese authorities dynamited a dike on the Yellow River, drowning thousands of Japanese soldiers-and thousands of Chinese peasants-while also flooding millions of square miles of land.
Similarly, if an army crawls on its stomach, as is often says, then feeding an army often requires hunting local animals, especially larger mammals that often have lower rates of reproduction. In the ongoing war in Sudan, poachers seeking meat for soldiers and civilians have had a tragic effect on bush animal populations in Garamba National Park, just across the border in the Democratic Republic of Congo. At one point, the number of elephants shrunk from 22,000 to 5,000, and there were only 15 white rhinos left alive.
Biological, Chemical, and Nuclear Weapons
The production, testing, transport and use of these advanced weapons is perhaps the single most destructive effects of war on the environment. Though their use has been strictly limited since the bombing of Japan by the U.S. military at the end of World War II, military analysts have grave concerns about the proliferation of nuclear material and chemical and biological weaponry. "We've been very fortunate that we have not seen the devastation that we might see," says Bruch.
Researchers point to the use of depleted uranium (DU) as one particularly dangerous military trend. DU is a byproduct of the uranium-enrichment process. Almost twice as dense as lead, it's valued in weapons for its ability to penetrate tank armor and other defenses. An estimated 320 tons of DU were used in the Gulf War in 1991; in addition to soil contamination, experts are concerned that soldiers and civilians may have been exposed to dangerous levels of the compound.
How Environmental Problems Lead to War
While the effects of war on the environment may be obvious, what's less clear are the ways that environmental damage itself leads to conflict. Factions in resource-poor countries like those in Africa, the Mideast, and Southeast Asia have historically used military force for material gain; they have few other options.
Bruch explains that once armed conflict begins, soldiers and populations under siege must find immediate sources of food, water, and shelter, so they're forced to adapt their thinking to short-term solutions, not long-term sustainability.
This short-term desperation leads to a vicious cycle of conflict, followed by people who meet their immediate needs in unsustainable ways, bringing deprivation and disillusionment, which then leads to more conflict. "One of the chief challenges is to break that cycle," Bruch says.
Can Warfare Protect Nature?
It seems counterintuitive, but some have argued that military conflicts often end up preserving the natural environment. "It's one of the findings that's utterly contrary to expectations," says Jurgen Brauer, Ph.D., professor of economics at Augusta State University in Augusta, Ga. "The most preserved area in all of Korea is the demilitarized zone because you have the exclusion of human activity," he says.
Other researchers have noted that despite the massive amounts of herbicide use during the Vietnam War, more forests have been lost in that country since the war ended than during it, due to peacetime commerce and Vietnam's quest for prosperity. The coal-black skies caused by the Kuwaiti oil fires in 1991 provided dramatic visual evidence of war-related environmental damage. However, these oil fires burned in one month roughly the amount of oil burned by the United States in a single day.
"Peace can be damaging, too," says Dabelko. "You have some of these ironic twists."
But experts are quick to emphasize that this is not an argument in favor of armed conflict. "War is not good for the environment," adds Brauer, who is also an author of "War and Nature: The Environmental Consequences of War in a Globalized World."
And Bruch notes that warfare only delays the environmental damage of peaceful human activity and commerce. "It may provide a respite, but the long-term effects of war aren't that different from what happens under commercial development," he says.
Winning the Peace
As military planning evolves, it becomes apparent that the environment now plays a greater role in successful combat, especially after an armed conflict ends. "At the end of the day, if you're trying to occupy an area, you have a strong incentive not to ruin it," Dabelko says. The aforementioned biblical quote from Deuteronomy about preserving trees is, perhaps, good advice for the ages.
And some warriors are learning that there's more to be gained from preserving the environment than in destroying it. In war-torn Mozambique, former military combatants have been hired to work together as park rangers protecting the wildlife and natural habitats that they once sought to destroy.
"That built bridges between the military and the park service. It has worked," Bruch says. "Natural resources can be very important in providing jobs and opportunities in post-conflict societies."