Earlier this year the discovery of a single cow with bovine spongiform encephalopathy, better known as mad cow disease, crippled the Canadian cattle market. In 2002 the mere rumor of foot-and-mouth disease in Kansas sent shock waves through the American cattle industry. And the discovery of exotic Newcastle disease in southern California led to the destruction of millions of chickens and prompted many countries to ban poultry coming from the area--and, in some cases, from the entire U.S.

Terrorists probably had nothing to do with the incidents, but agriculture and homeland security officials cite these and similar events in describing the possible effects of a bioterror attack on domestic agriculture. Officials take such a threat seriously--the terrorist group Al Qaeda long ago put the U.S. food supply on its list of potential targets. The federal government is working to bolster the nation's readiness for an agroterror attack--and some of their assessments suggest significant vulnerabilities that critics say are not getting enough attention.

From farm crops and animals through the processing system to the grocery store, the food supply chain provides numerous opportunities for attack. Moreover, the system would ensure rapid disease progression: animals are moved often and quickly, and anticrop agents can be spread by the wind. Since the September 11 attacks, the U.S. Department of Agriculture has hired new inspectors and strengthened its diagnostic capabilities around the country. The Food and Drug Administration has bolstered food safety rules and made it easier for investigators to trace the origins of an outbreak. The Department of Homeland Security has assumed responsibility for the inspection of agricultural products entering the country. And states are working on their own efforts to educate and ensure proper coordination in the event of an outbreak.

In part to determine the effectiveness of such preparations, the Pentagon organized two classified exercises called Silent Prairie, part of an ongoing series of simulations run by the National Defense University (NDU). In the February exercise, members of Congress, state officials and government representatives dealt with foot-and-mouth disease. The USDA had already calculated that the highly virulent sickness could spread to as many as 25 states in as little as five days. The Silent Prairie simulation produced equally horrifying results: more than one third of the nation's cattle herds wound up infected, according to Zdenka Willis, a navy captain at the NDU. Representative Devin Nunes of California, who hails from a district heavily dependent on farming, remarks that such an outbreak "would be devastating to our food supply and our economy."

Thomas McGinn, head of the North Carolina emergency programs office and a Silent Prairie consultant, says that too many people see agricultural terror incidents as local events, akin to "lobbing a grenade over enemy lines." But the rapid spread of foot-and-mouth makes it "a homeland security issue, immediately," he insists. Indeed, according to an NDU paper outlining the Silent Prairie results, "response to an agricultural bioterrorism attack could require significantly more resources than the attack on the World Trade Center."

The expense of coping with agroterror is why Peter Chalk, an analyst with the RAND Corporation, a Santa Monica, Calif., think tank, remains concerned about what he deems insufficient federal focus on the threat of "economically catastrophic" attacks. Chalk notes that some improvements have been made in the past year, notably in such areas as security at food-processing facilities. But "I haven't really seen much in terms of concrete policy taking place," he says. Chalk wants the U.S. to undertake a "comprehensive threat analysis" as well as an assessment of how much money is needed and where it should be spent.

McGinn believes that the federal government should do for agriculture what it has done for human health since 9/11: dramatically increase state and local capabilities to detect diseases and educate medical personnel as well as the public. "The ability to feed ourselves has become part of the critical infrastructure of our country," McGinn states. "We've got to increase the security in our food system all the way from the farm to the fork."

Daniel G. Dupont, who edits InsideDefense.com, an online news service in Washington, D.C., wrote about nonlethal knockout gases in the January issue.