Most Americans once thought of warfare solely in terms of tanks, planes and ballistic missiles. That was before Sept. 11, 2001.

Now, an ancient military tactic employed for centuries with deadly effect has gotten the attention of terrorism experts. They have even put a name to it — asymmetric warfare, an ancient tactic based on a simple premise.

“What this means basically is that if you have an adversary, you use his strength against him,” says Robert Norton, an Alabama Cooperative Extension System biosecurity specialist and Auburn University associate professor of poultry science.

Traditionally, this has involved depriving an enemy of his food or water — a practice that military underdogs have used throughout history to cut big enemies down to size. As Norton observes, “Once an enemy is deprived of food or water, he becomes soft and can be taken on more directly.”

These tactics aren't limited to food and water.

At a cost of only a half million dollars, radical Islamicists, 21st century military underdogs, used jetliners — American jetliners — as weapons to inflict thousands of casualties and hobble the U.S. economy for months. As President Bush observed, the attacks drove home with brutal clarity the fact that “shadowy networks of individuals can bring great chaos and suffering to our shores for far less than it costs to purchase a single tank.”

“It was a classic demonstration of the effects of asymmetric warfare,” Norton says, adding that it is probably only the first of a series of attacks that will occur with much greater severity.

Sharing Norton's views is Col. Orson Pratt, a recent contributor to the U.S. Army's Professional Writing Collection who argues similar attacks will be employed against other sectors of the U.S. economy. Much like Sept 11, they won't involve bombs or missiles but something far less conventional — microbes, plants, animals or some other organism targeted against the U.S. agricultural sector.

Coordinated introductions of these organisms, Pratt says, would wreak havoc throughout the economy. It not only would “inflict tremendous economic and psychological damage,” he says, but “weaken the United States in a way to achieve a more equitable political, economic and military balance of power.”

A single introduction of foot-and-mouth disease on a U.S. cattle farm, for example, could lead to the destruction of millions of cows, even leading to a worldwide ban of U.S. cattle exports lasting years. This does not even account for other diseases, which could be intentionally introduced at the same time, Pratt says.

The likelihood of such an attack remains uncertain, Norton says. What is certain is that the strategy closely corresponds with terrorist mastermind Osama bin Laden's personal views on asymmetric warfare, Norton says.

“He has often admitted he can't go against us head to head on the battlefield because he knows he'll lose,” Norton says. “But he does understand — and he's stated this repeatedly — that he can exploit our weak points.

“One of the things he has talked about consistently is our economy — the economy, the economy, the economy."

Documents retrieved from al Qaeda hideouts in Afghanistan and other places throughout the world also indicate terrorists have “taken a serious look at agriculture,” Norton says.

Very little expertise is required to mount an economically devastating attack on the U.S. agricultural sector — one reason why terrorist groups apparently find this approach so appealing.

The good news, Norton says, is that federal authorities also are taking a serious look at agriculture, identifying steps that can be taken to safeguard farming operations against terrorist attacks.

Until the Sept. 11 attacks, U.S. policymakers were slow in perceiving these risks, Norton says, but things are changing. The U.S. Department of Agriculture is developing a rapid response network that will operate in the event of such an attack. This network and similar efforts, which will be supported by a projected $381 million in 2005, is part of an ambitious USDA plan to safeguard the nation's farms against potentially devastating terrorist attacks.