The US Agricultural Sector: A New Target for Terrorism?


Feb 9, 2001

This commentary originally appeared in Jane's Intelligence Review on February 9, 2001.

Reproduced with permission from Jane's Information Group.

The potential for terrorists to disrupt economies and societies by introducing pathogens into the food chain and livestock is only now being taken seriously by government agencies, argues Peter Chalk.

THE ISSUE of mass destruction terrorism has evoked considerable attention in the USA, at the policy and academic levels, particularly since Aum Shinriyko launched a sarin nerve gas attack on the Tokyo subway system in 1995. Reflecting this, the US federal anti-terrorism budget has ballooned in the last few years. In Fiscal Year 2001 (FY01) US$1.555 billion has been requested to augment homeland defences against chemical, biological, radiological and nuclear attacks, more than double the figure allocated in FY98 ($645 million).

One somewhat surprising addition to the 2001 budget is a line-item for $39.8 million to be apportioned to the US Department of Agriculture (USDA), a federal body that has not in the past received much attention in US national security contingencies. Its inclusion reflects a growing concern that the agricultural sector, which accounts for roughly one sixth of US GDP - more if related food industries and suppliers are factored in - may become the target of a future act of chemical or biological (CB) terrorism. This concern has been generated by a growing realisation that CB attacks against livestock and the food chain are substantially easier and less risky to carry out than those directed at civilian targets.

Floyd Horn, the USDA's top administrator, has testified on the threat of 'agroterrorism' before several Senate and Congressional hearings in the last few years. He believes that "a biological attack is quite plausible". According to Horn, the agents for such an attack are readily available, and the economic consequences significant. Public confidence in the government would almost certainly be shattered by such an attack.

Capability requirements

Livestock attacks

Weaponising biological pathogens to destroy agricultural livestock is a far easier process than creating munitions designed to kill people. Several factors account for this:

- there are many more agents that are lethal and highly contagious to animals than is the case with humans, many of which are not routinely vaccinated against. At least 22 such diseases are known to exist. Most are also environmentally resilient - being able to exist for long periods of time in and on organic matter - and are reasonably easy to acquire and produce;

- US livestock has become progressively more disease prone in recent years as a result of intensive antibiotic and steroid programmes and husbandry changes designed to elevate the volume, quality and quantity of meat production, as well as satisfy the specific requirements of potential vendors. These biotechnic modifications, which can include anything from branding and disinfectant sterilisation treatments to dehorning, castration and hormone injections, have combined to dramatically elevate the stress levels of exposed livestock. This has lowered the natural tolerance of farm animals to diseases and increased the volume of bacteria that would normally be shed in the event of infection; and

- problems of pathogenic dissemination have been largely circumvented due to the intensive way in which US farm animals are currently reared, bred and transported. Most US dairies can be expected to contain at least 1,500 lactating cows at any one time; some of the largest premises housing up to 10,000 animals. The outbreak of a contagious disease at one of these facilities would be very difficult to control and could necessitate the destruction of all the livestock, a formidable and expensive task.

Foodborne attacks

The capability requirements for carrying out a foodborne attack are rudimentary, and certainly more so than those necessary for an airborne assault. There are a myriad of possible agents and vectors that could be used, most of which are either readily available or do not require any substantial scientific knowledge to isolate and develop.

Moreover, developments in the farm-to-table logistics chain has increased the number of potential 'entry points' for CB contamination. This has helped to augment the technical ease of disseminating contaminants into plant, vegetable, dairy and fruit-based products, particularly given the relatively low level of bio-security and surveillance that exists at many of the food processing and animal rendering plants throughout the USA.

Risk potential

Quite apart from their relative ease, attacks against agriculture are comparatively risk free in the sense that they neither cross the threshold of mass destruction, nor, in most cases, do they represent a direct threat to those carrying them out. Destroying pig or cattle production would be unlikely to attract the same response as a more 'conventional' bioattack against a heavily populated centre such as Los Angeles or San Francisco.

Equally, because there is no large-scale loss of human life, perpetrators are unlikely to be affected by residual feelings of moral guilt or, indeed, substantially weakened by reduced popular support - both potential costs of civilian-oriented operations.

Also, biological attacks against livestock can be carried out in such a way that they imitate natural or common disease occurrences. This complicates accurate epidemiological investigation and greatly reduces risks to the perpetrators of possible detection.

In terms of personal risk, biological agroterrorism is also more attractive than experimenting with human viral or bacterial agents as virulent non-zoonotic diseases, such as hog cholera, rinderpest, African swine fever and foot and mouth disease (FMD), can always be used. While all of these infections are lethal to ruminant animal populations, they cannot be passed on to people and, therefore, pose no risk in the form of accidental or latent contamination.

The relative ease of weaponising biological agents against livestock (or otherwise introducing them into the food chain), together with the largely risk-free nature of this form of aggression, have been identified by the Gilmore Commission - a Congressionally mandated panel assembled to assess the potential threat of weapons of mass destruction (WMD) terrorism in the USA - as important factors in the potential use of this form of 'exotic' terrorism.

According to the Gilmore Commission: "[A] concerted biological attack against an agricultural target offers terrorists a virtually risk-free form of assault, which has a high probability of success." This is important as one of the main factors that appears to have limited terrorist experimentation with WMD is a lack of predictability: the perceived ability to carry out the operation in question with minimal risk to the terrorists themselves.


Notwithstanding its operational ease, there would be little point in investing time and effort in carrying out attacks against animals and crops if the impact of such action was unlikely to be that great. However, this is where the real potential threat of agroterror comes in. The ramifications of a concerted bioassault on the US meat and food base would be far-reaching and could extend beyond the immediate agricultural community to affect other segments of society.

Economic destabilisation

Perhaps one of the most immediate effects of a major act of biological agroterrorism would be to create economic destabilisation. As Corrie Brown, a veterinary pathologist at the University of Georgia, argues: "A terrorist wishing to cause severe and reverberating financial consequences could simply introduce a foreign disease into American livestock, which would set off a chain reaction touching virtually every citizen's pocketbook."

The economic consequences of such an attack could be felt in three main ways:

- direct economic losses resulting from containment measures and the destruction of disease-ridden crops and livestock. In 1983-84, for instance, the US poultry industry was hit by a particularly pathogenic strain of avian influenza (AI). Eradicating the disease cost the government $63 million, contributing to a $349 million rise in turkey, chicken and egg prices in the first six months of the outbreak;

- indirect multiplier effects. The extent of these costs can be enormous. In the UK, for instance, the outbreak of bovine spongiform encephalopathy (BSE) in the 1990s cost the UK government $9-14 billion in compensation paid to farmers affected by the slaughter of their cattle, and employees laid off in the dairy and beef industries; and l international costs arising from the institution of protective embargoes by major trading partners. Following the 1997 outbreak of FMD in Taiwan, for instance, an indefinite ban was imposed on the country's pork exports, causing Taipei's GDP to drop by 2% almost overnight.

Loss of confidence

A successful bioattack against the US agricultural sector would undermine confidence in central government and encourage support for instate governance. Successfully releasing contagious agents against crops and livestock would cause people to lose confidence in the safety of food supply and could lead them to question the effectiveness of existing contingency planning against WMD in general.

People may begin to equate the ability to infect animals with an enhanced capacity to target humans, calling for greater emergency planning in major cities, more stockpiling of vaccines and increased surveillance of 'high-risk' groups (which has implications for civil liberties). Critics would almost certainly demand to know why the intelligence services failed to detect that an attack was imminent and why the agricultural sector was left exposed. The combined effect would be to initiate a chain of socio-political reactions and events, which, if not carefully managed, could fundamentally alter the relationship between citizen and government at state and federal levels.

The actual mechanics of dealing with an act of agricultural bioterrorism could also generate widespread public criticism. Containing a major disease outbreak would almost certainly necessitate the slaughter of hundreds, if not thousands, of animals (the 1999 Hendra encephalitis epidemic in Malaysia, for instance, led to over 800,000 pigs being shot).

Actually culling large numbers of animals, despite being a scientifically justifiable way of containing viral and bacterial dissemination, would generate vigorous opposition from affected farmers and animal rights movements, particularly if such operations involved the destruction of high-risk but non-disease-showing livestock and wildlife.

Roger Breeze, associate director of the USDA's Agriculture Research Service, says the fact that the USA has not experienced a major cattle or sheep epidemic in the era of television is extremely important in this regard, as it effectively means that "no visual point of reference has been available to prepare the public for the consequences of containing such an occurrence".

Even in the unlikely event that large-scale culling operations were accepted, the actual removal of carcasses would be just as challenging. The quickest and easiest way to dispose of contaminated animal waste is either by burying corpses in landfills covered with quicklime or by incinerating them in pits lined with burning tyres. However, utilising such methods in an ecologically 'friendly' manner is only feasible if a small number of bodies need to be dealt with. Burning thousands of carcasses with rubber tyres would create a huge, smouldering open fire, as well as a highly visible atmospheric pollution problem. Both would attract widespread criticism.

Mass burial is likely to be just as contentious, not least because of the risk it would pose to ground water supplies. It would also render large areas of land unuseable for many years (a particular concern to heavily urbanised states).

On the other hand, the longer officials prevaricate and leave diseased carcasses out in the open, the higher the probability that they will act as a source for future epidemic - an equally unacceptable outcome.

Apart from the risk of precipitating civil disturbances, there is also the possibility that mass culling, burning and incineration operations might spark acts of terrorism by animal rights and environmental extremists. The police authorities in California are very concerned at the prospects of such extremism, not least because of the state's history of radical, socially inspired activism and the existence of many sympathisers that express strong support for militant groups such as the Earth Liberation Front, the Animal Rights Militia and the Animal Liberation Front.

Social instability

Beyond the immediate economic and political effects, bioterrorist assaults against agriculture have the potential to create mass panic and could, possibly, stimulate socially disruptive rural-urban migrations. Several animal diseases are zoonotic in nature, meaning that they have the ability to 'jump' species and affect humans. Principal among these are AI, the West Nile virus (WNV), Japanese encephalitis and BSE.

Should an epidemic of any one of these diseases occur in the USA, it could have severe repercussions in terms of creating a mass public scare, particularly if human deaths occurred. Terrorists could use this to their advantage, allowing them to create a general atmosphere of fear and anxiety without actually having to carry out indiscriminate civilian-oriented attacks. As terrorist expert Dr Bruce Hoffman observes: "It gets the terrorists' coercive point across but doesn't necessarily cross the threshold of killing people, and thus doesn't create the same kind of backlash."

The outbreak in New York of the WNV in 1999 provides a good example of how quickly the effects of such viruses can spread and the extent to which they can impact on the psyche of the ordinary citizen. The disease, which was previously unknown to the USA, quickly spread to humans, several of whom subsequently died as a result of massive heart and liver failure. A major public health scare ensued, the dimensions of which were exacerbated by the epidemiological difficulty of definitively determining the pathogen's type, source and transmission mode.

A foodborne attack would do equally as well in terms of causing mass panic and social instability. Because most processed food is disseminated to a large 'catchment' area in an extremely short period of time, a single case of contamination could have significant ramifications in terms of psychological effects. This is particularly so if the source of the problem was not immediately apparent, and if multiple chronic or acute ailments ensued.

Economic crime and blackmail

It should also be noted that the low probability of detecting intentional biological assaults against agriculture makes this modus operandi an ideal and largely risk-free way for terrorists (and other criminals) to raise money. The USDA believes that one particularly effective way of achieving this would be to manipulate "the US agricultural future commodity markets through pathogen and pest introductions".

An attack that severely crippled the US cattle industry, for instance, would be sure to result in a major increase in demand, and corresponding price rise, for the products of the country's major beef and milk competitors. An astute terrorist could take advantage of this by simply investing in appropriate stock before carrying out an assault.

The potential impact and mechanics of agroterrorism also gives this form of aggression a high payoff in terms of more basic extortion and coercive blackmail. Unlike human-directed biological threats, terrorists would have the advantage of establishing the credibility of their resolve by actually carrying out a large-scale livestock or foodborne attack without attracting retaliation from governing entities that no longer feel they have anything left to lose. Also, given the enormous direct and latent damage that could be inflicted by repeat attacks, state and federal governments would have a strong incentive to negotiate, a central consideration in any blackmail attempt.

Is this terrorism?

The absence of direct physical violence against human targets has prompted certain commentators to exclude any agricultural attacks from the terrorism lexicon. However, if terrorism is defined as a psychological act of criminal violence designed to destabilise society and influence government policies, then attacks against agriculture could be considered terrorist in nature.

As noted above, the ramifications of a concerted bioassault on a country's meat and nutritional base would certainly be far-reaching and could extend beyond the immediate agricultural community to affect other segments of society. Moreover, agroterrorism does not necessarily preclude the possibility of violence against civilian populations as zoonotic diseases and foodborne pathogens can always be used.

Despite the ease and potentially severe implications of carrying out biological attacks against agriculture, to date only a handful of actual or threatened incidents have occurred. If there are no real technological or psychological constraints to employing biological weapons against agriculture, why haven't terrorists made more use of this modus operandi, especially given its potential to cause significant economic, political and social upheaval? One reason could be that terrorists haven't thought through the full implications of deliberately targeting agricultural livestock and produce. According to this interpretation, it may only be a matter of time before more instances of this type of aggression take place.

Another possibility may be that deliberate sabotage is traditionally not something health officials have actively looked for when investigating crop or animal disease outbreaks. The implication here is that more acts may have actually taken place than are known about. Animal and plant health officials in Washington concede this is a possibility, acknowledging that in most countries (including the USA) the tendency is to automatically assume that disease outbreaks are naturally occurring events. The inevitable consequence has been epidemiological investigations that seldom consider the possibility of deliberate pathogenic introduction.

Finally, it could be that terrorists consider this form of aggression to be too 'dry' in comparison to traditional bombings, in the sense that attacks against crops and animals do not produce immediate, visible effects. The impact, while significant, is delayed, lacking a single point for the media to focus on. As such, the fact that biological agro-terrorism has not emerged as more of a problem is perhaps understandable.

However, it would be wrong to assume that this precludes the possibility of a switch to this form of violence. Infrastructure attacks, if carried out effectively, can be just as devastating as more traditional terrorist actions, something that is especially true with regards to agriculture.

The ability to direct a state's resources towards stemming potential epidemics gives agroterrorists faced with significant power asymmetries considerable leverage in pursuing their agendas. Moreover, as the WNV outbreak in New York demonstrates, a disease outbreak that actually kills human beings has the potential to attract considerable media interest, locally, regionally, nationally and even internationally.

It is also perhaps worth noting that, at least at the nation-state level, the potential viability of anti-crop and livestock agents has long been recognised and reflected in weaponisation programmes in Europe during the First World War, the USSR, the USA, Iraq and South Africa. It is in this context that Colonel Robert Kadlec, a US Air Force biowarfare expert, has somewhat ominously concluded that: "Agroterror offers an adversary the means to wage a potentially subtle yet devastating form of warfare, one which would impact on the political, social and economic sectors of society and potentially threaten national survival itself."

Professor Peter Chalk is an expert on transnational terrorism at the RAND Corporation in Washington.

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