The potential for terrorist attacks against agricultural targets (agroterrorism) is increasingly recognized as a national security threat, especially after the events of September 11, 2001. In this context, agroterrorism is defined as the deliberate introduction of an animal or plant disease with the goal of generating fear over the safety of food, causing economic losses, and/or undermining social stability. The response to the threat of agroterrorism has come to be called "food defense." An agroterrorist event would usually involve bioterrorism, since likely vectors include pathogens such as a viruses, bacteria, or fungi. People more generally associate bioterrorism with outbreaks of human illness (e.g., anthrax or smallpox), rather than diseases affecting animals or plants. The goal of agroterrorism is not killing cows or plants. These are the means to the end of causing economic crises in the agricultural and food industries, social unrest, and loss of confidence in government. Human health could be at risk through contaminated food or if an animal pathogen is transmissible to humans (zoonotic). While agriculture may not be a terrorist's first choice because it lacks the "shock factor" of more traditional terrorist targets, an increasing number of terrorism analysts consider it a viable secondary target. Agroterrorism could be a low-cost but highly effective means toward an al-Qaeda goal of destroying the United States' economy. Evidence that agriculture and food are potential al Qaeda targets came in 2002 when terrorist hideouts in Afghanistan were found containing agricultural documents and manuals describing ways to make animal and plant poisons. Agriculture has several characteristics that pose unique problems: Farms are geographically disbursed in unsecured environments (e.g., open fields and pastures throughout the countryside). While some livestock are housed in facilities that can be secured, agriculture generally requires large expanses of land that are difficult to secure. Livestock frequently are concentrated in confined locations (e.g., feedlots with thousands of cattle in open-air pens, farms with tens of thousands of pigs, or barns with hundreds of thousands of poultry) allowing diseases to infect more animals quickly. Concentration in slaughter, processing also makes large scale contamination possible. The number of lethal and contagious biological agents is greater for plants and animals than for humans. Most of these diseases are environmentally resilient, endemic in foreign countries, and not harmful to humans—making it easier for terrorists to acquire, handle, and deploy the pathogens. Live animals, grain, and processed food products are routinely transported and commingled in the production and processing system. These factors circumvent natural barriers that could slow pathogenic dissemination. International trade in livestock, grains, and food products is often tied to disease-free status. The presence (or rumor ) of certain pests or diseases in a country can quickly stop exports of a commodity, cause domestic consumption to drop, disrupt commodities markets, and can take months or years to recover. The past success of keeping many diseases out of the U.S. means that many veterinarians and scientists lack direct experience with foreign diseases. This may delay recognition of symptoms in case of an outbreak, and the ability to respond to an outbreak. Thus, the general susceptibility of the agriculture and food industry to bioterrorism is difficult to address in a systematic way due to the geographically dispersed, yet industrially concentrated nature of the industry, and the inherent biology of growing plants and raising animals. In an attack, the agricultural sector would suffer economically from plant and animal health losses, and the supply of food and fiber may be reduced. The demand for foods targeted in an attack may decline (e.g., dairy, beef, pork, poultry, grains, fruit, or vegetables), while demand for substitute foods may rise. Economic losses would accrue to individuals, businesses, and governments through costs to contain and eradicate the disease, and to dispose of contaminated products. More losses would accumulate as the supply chain is disrupted from farm-to-fork. Domestic markets for food may drop, and trade restrictions could be imposed on U.S. exports. The economic impact would range from farmers to input suppliers, food processors, transportation, retailers, and food service providers. Significant threats to the currently-held notion of food security could affect our social order. Fear of food shortages moved further from American psyche as the United States from an agrarian society to the industrial and information age. Nevertheless, food remains an important element of everyone's daily routine and is necessary for survival. This report addresses the use of biological weapons against agriculture, rather than terrorists using agricultural inputs or equipment in attacks against non-agricultural targets. For example, the Department of Transportation issued regulations for developing security plans to protect dangerous agricultural materials such as fuels, chemicals, and fertilizers against theft. Legislation proposed in 2005-2006 ( H.R. 3197 , H.R. 1389 , and S. 1141 , 109 th Congress) would have restricted the handling of ammonium nitrate, an agricultural fertilizer that can be converted into an explosive. Another example is the concern over misuse of small aircraft, particularly crop-dusters, to spread biological weapons. This report focuses primarily on biological weapons (rather than chemical weapons) because biological weapons generally are considered the more potent agroterrorism threat. This report also focuses more on agricultural production than food processing and distribution, although the later is discussed. For more on chemical and biological weapons, see CRS Report RL32391, Small-scale Terrorist Attacks Using Chemical and Biological Agents: An Assessment Framework and Preliminary Comparisons , by [author name scrubbed] and [author name scrubbed] (pdf); and CRS Report RL31669, Terrorism: Background on Chemical, Biological, and Toxin Weapons and Options for Lessening Their Impact , by [author name scrubbed]. Even before September 11, 2001, and the focus on terrorist threats that ensued, references to agroterrorism and/or agricultural bioweapons can be found in the government, academia, and the press. For example, the Gilmore Commission (on terrorism), in its first report to Congress in 1999, noted that "... a biological attack against an agricultural target offers terrorists a virtually risk-free form of assault, which has a high probability of success and which also has the prospect of obtaining political objectives, such as undermining confidence in the ability of government or giving the terrorists an improved bargaining position." Senator Roberts from Kansas also raised the awareness of agroterrorism with a hearing of the Senate Committee on Armed Services in 1999. However, as the 20 th century ended, agriculture and food production received less attention, or sometimes was overlooked, in federal counterterrorism and homeland security activities. A Presidential directive in 1998 on protecting critical infrastructure did not include agriculture and food. Agriculture was added to this list only in December 2003. Thus, after what many observers claim to be a slow start after September 11, 2001, agriculture now is garnering more attention in the expanding field of terrorism studies and policies. Agroterrorism received heightened national attention in December 2004 when then-Secretary of Health and Human Services Tommy Thompson said in his resignation speech, "For the life of me, I cannot understand why the terrorists have not attacked our food supply because it is so easy to do." Congress has held hearings on agroterrorism and, while addressing terrorism more broadly, has implemented laws and appropriations with provisions important to agriculture. The Government Accountability Office (GAO) has studied aspects of food safety, border inspections, interagency coordination, and physical security with respect to agroterrorism. The executive branch has responded by implementing the new laws, issuing several presidential directives, creating terrorism and agroterrorism task forces, and publishing protection and response plans. The law enforcement community has recognized agroterrorism as a threat, highlighted by FBI and JTTF (Joint Terrorism Task Force) sponsorship of an annual conference on agroterrorism. The 9/11 Commission (National Commission on Terrorist Attacks Upon the United States) does not make any direct references to agroterrorism or terrorism on the food supply in its 2004 report. However, agriculture obviously would be affected, along with other sectors of the economy, by some of the commission's recommendations regarding coordination of intelligence, information sharing, and first responders. An evaluation of those separate issues, however, is outside the scope of this report. Agriculture and the food industry are very important to the social, economic, and arguably, the political stability of the United States. Although farming employs less than 2% of the of the country's workforce, 16% of the workforce is involved in the food and fiber sector, ranging from farmers and input suppliers, to processors, shippers, grocers, and restaurateurs. In 2002, the food and fiber sector contributed $1.2 trillion, or 11% to the gross domestic product (GDP), even though the farm sector itself contributed less than 1%. Gross farm sales exceeded $200 billion, and are relatively concentrated throughout the Midwest, parts of the East Coast, and California ( Figure 1 ). Production is split nearly evenly between crops and livestock. In 2002, livestock inventories included 95 million cattle, and 60 million hogs. Farm sales of broilers and other meat-type chickens exceeded 8.5 billion birds. Agriculture in the U.S. is technologically advanced and efficient. This productivity allows Americans to spend only about 10% of their disposable income on food (both at home and away from home). Productivity increases over time have allowed the share of disposable income spent on food in the U.S. to fall from 23% in 1929 to 10% in 2003. The United States has the lowest spending on food prepared at home (6.5%) compared to the rest of the world, which ranges from 10%-15% for most developed countries and 30% or higher for some developing countries.