Global biosecurity presents international challenges because the majority of instances of novel organism introductions are due to international movements of goods, food and people and the likelihood of introduced agents crossing political boundaries. The inherent vulnerability of environments to introductions of alien, or non-indigenous, biological agents is due to the greater ecological vulnerability to these exotic entrants in the receiving environment. Agencies and individuals responsible for approving intentional introductions of beneficial organisms recognize this relationship and consider potential impacts in risk assessments prior to release of the organisms. However, some of those responsible for detection and control of novel pathogens and pests, introduced either inadvertently or intentionally, lack extensive training in ecology, environmental biology, and pathology, and may therefore underestimate the risk from such events. The latter is a key factor in the case of food safety. Europe is particularly vulnerable to cross-border movement of introduced agents, and one response to this has been the recent revision of plant health regimes throughout the European Union. Other responses include project-based initiatives, such as PLANTFOODSEC.