Mark G. Stewart is Professor of Civil Engineering and Director of the Centre for Infrastructure Performance and Reliability at The University of Newcastle in Australia. He is co-author of Probabilistic Risk Assessment of Engineering Systems (Chapman & Hall, 1997, and Japanese edition in 2003), and has published more than 400 technical papers and reports. He has 30 years of experience in probabilistic risk and vulnerability assessment of infrastructure and secu¬rity systems that are subject to man-made and natural hazards. Professor Stewart has received extensive Australian Research Council support, including an Australian Professorial Fellowship, to develop probabilistic risk-modelling techniques for infrastructure subject to military and terrorist explosive blasts, and cost-benefit assessments of aviation security, policing, and counter-terrorism protective measures for critical infrastructure.