Ever since the Romans sowed salt on Carthaginian farm fields during the third Punic War, right up until the destruction of Kuwaiti oil wells by Iraq during the Gulf War, the environment has been both a strategic element and a victim of warfare.
But it's only been in recent decades that the US military has had to face the enormous expense and political challenge of becoming "greener." Today, that challenge is growing.
In the wake of the recent terrorist attacks in New York and Washington, major national environmental groups have muted their criticisms of the Bush administration.
From Alaska to Puerto Rico, however, the armed services are under increasing pressure to consider the environmental impact of their operations.
Local communities - typically thought of as supportive of nearby military bases - are asking why military units should be exempt from federal laws like the Clean Water Act. Minority and native groups, which often live closest to military facilities, see the issue as one of "environmental justice."
Environmental activists note that wide-open bases (particularly in the West) are becoming prime habitat for endangered species, as urban sprawl crowds out other areas.
Some recent examples: At the prodding of local officials, Congress's General Accounting Office (GAO) is investigating World War I-era chemical munitions buried just outside Washington, D.C. County officials in northern California just denied the Army's request for an exemption to air-pollution laws so that it could burn old bombs and rockets. A coalition of environmental groups is taking legal steps to block Bush administration plans to deploy antimissile missiles near Fairbanks, Alaska.
The Defense Department is faced with cleaning up the contamination from decaying ordnance, mothballed warships, fuels, solvents, and other pollutants left over from the wars of the 20th century. Most of this is in this country, but some is overseas as well, including 19 million gallons of the deadly herbicide Agent Orange sprayed on the jungles of Vietnam, which the US is now helping to clean up.
Ironically, because other kinds of development were prohibited on (and sometimes near) military bases and Energy Department weapons plants, such land has become increasingly valuable habitat for endangered species.
For example, the Hanford Reach portion of the Columbia River in central Washington State, which flows through a highly secure area where the radioactive material for nuclear weapons was manufactured, is one of the last untrammeled spawning areas for salmon.
The Pentagon is working hard on such issues, spending more than $5 billion a year on its "environmental security program." Meanwhile, it's having to adjust its training operations to take account of things like the endangered red-cockaded woodpecker at Fort Bragg, N.C. In some cases, the services are working with the Nature Conservancy and other environmental groups to protect wildlife habitat.
But that's not enough for some critics. The Maine-based Military Toxics Project recently reported that "military exemptions from laws and lax enforcement by regulatory agencies have produced over 27,000 toxic hot spots on 8,500 military properties." The GAO estimates that it could cost more than $100 billion to clean up Defense Department training ranges.
A proposal in Congress would require the military to comply with the same environmental regulations as private businesses, landowners, and other government agencies.
"Is it really fair that the military - a branch of the federal government - is exempt from its own laws?" asks Rep. Bob Filner (D) of California, whose San Diego district is in an area dotted with military bases.
The controversy is likely to heat up, particularly as the armed services push for more land on which to test and train with advanced weapons systems. In congressional testimony earlier this year, senior officers complained of "encroachment" that is hampering their military readiness.
"The most challenging legal requirements to Navy readiness are the Marine Mammal Protection Act, Endangered Species Act, Migratory Bird Act, and the Clean Air Act," Vice Admiral James Amerault, deputy chief of naval operations for fleet readiness and logistics, told the House Armed Services Committee in May.
Speaking of the "encroachment" on target ranges and other training facilities, Maj. Gen. Edward Hanlon, USMC, warned senators in March that "we are training a generation of marines who will have less experience in the intricacies of combat operations."
"If encroachment continues, many of today's junior leaders may initially face the full challenges of combat not during training, but during combat," said General Hanlon, commanding general of Camp Pendleton in California, which includes habitat for 17 threatened and endangered species.
Meanwhile, a philosophical debate within the armed services considers whether the means and methods of actual warfare - not just training - should take into account the long-range environmental impact. That is, should the guy in the tank or the bomber, in the heat of combat, really care about whether he's destroying some pristine wilderness or wetlands?
"As a general consideration, the US should include environmental effects as an issue of central value along with politics, economics, and social effects when deciding whether or not to wage war and, if so, in what manner," Col. Richard Fisher, US Air Force Reserve, wrote in an article for Aerospace Power Chronicles, published by the Air Force. "It may well be that the potential long-term environmental risk due to loss of productivity outweighs the importance of other considerations."
Colonel Fisher's assertion may be heresy to some whose whole career centers on fighting - and winning - in the name of national security.
But that such questions are even being considered is a sign that profound changes are happening in the relationship of warfare and the environment. All of which puts increasing pressure on the armed services, which are looking for some political relief even as they must spend more money and effort dealing with their impact on nature.
"We can, and are doing much to protect the environment," says Hanlon. "However, we cannot be expected to shoulder a disproportionate share of environmental protection and still meet our readiness."