Plant pathogens as agroterrorist weapons: assessment of the threat for European agriculture and forestry

Malevolent use of plant pathogens in an act of agroterrorism represents a potential threat for European agriculture and forestry. We investigated the risk of agroterrorism sensu lato, which is raising debates among the community of plant pathologists. In the absence of a previous unambiguous definition of agroterrorism we characterized the risk for Europe by taking into account the multiplicity of the threat, of the perpetrator's objectives, and of potential modus operandi. To this end, we have applied a three-step methodology involving: (1) the building of a list of candidate pathogens, (2) a scenario-based exploration of potential agroterrorist acts, and (3) the design of a risk evaluation scheme (RES), derived from the standard pest risk analysis (PRA). We adopted a congruent risk assessment strategy consisting of coupling the foresight exercise (assignment of nine key pathogens extracted from the list to nine scenarios and comparison of different intrinsic criteria) to the analytical assessment (application of the RES to the nine key pathogens and qualitative analysis resulting in a pentagonal star plot representing risk profiles). Analysis was performed by non-experts on the selected diseases, and thus enabled a comparison between crops or pathogens on the basis of the characterization of the threat. The risk, considered in its hybrid dimension (both factual because it refers to crop protection and an effective stake, and also irrational because it refers to bioterrorism, a vague and unobservable concept) was characterized exhaustively for the selected plant pathogens and the success of a malevolent act appeared to be much more uncertain than believed. However, agroterrorism should be considered as a plausible threat, potentially more important by the consequences of the securitization of the concept, which could imply disruption of regulations and trade, than by direct damaging consequences on European crops. There is probably not a single short-list of threatening pathogens: different pathogens would be most threatening for different purposes, for different perpetrators, and for different target crops.