This paper contributes not only to the derivation of vulnerability indicators but also to the development of a novel framework for vulnerability assessment by drawing a clear link between environmental stress and state susceptibility, on the one hand, and environmental crisis, on the other hand, using the concept of the Security Diagram. The underlying assumption of the Security Diagram is that a higher level of vulnerability due to the combined impacts of environ-mental stress and state susceptibility causes a higher probability of crisis. A unique feature of the Security Diagram is the possibility of embedding crisis probability curves in the diagram. These curves are a convenient yardstick for measuring the degree of vulnerability of a state over time, or comparing vulnerability across regions and countries for a particular period. Using methods such as fuzzy logic, MaxIndex and binary choice models, a Security Diagram for the state of Andhra Pradesh in India for the period 1970-1995 is constructed.