Interactive learning environments are increasingly used to help people better deal with complex situations. One way to improve decision making effectiveness is to train systems thinking skills using interactive simulations in order to reduce the occurrence of “unintended side-effects” of interventions and catastrophic failures. We present a prototype training procedure intended for military officers and civilian personnel engaged in “full spectrum” operations. The Complex Decision Making simulation environment (CODEM) is the core of the proposed training procedure. CODEM aims to improve systems thinking skills, adaptability and other abilities associated with the integrative concept of cognitive readiness. Four training scenarios are designed to reproduce key properties of complex decision making situations. An intelligent tutor providing corrective feedback on decision making behaviors is integrated into each scenario. The tutor interventions help avoid tunnel vision (i.e., the opposite of systems thinking) by discouraging the use of overly simple heuristics. Nine behavioral metrics are monitored by the intelligent tutor - five are related to information seeking behaviors, and four are related to specific decision patterns. The effectiveness of this prototype training procedure is currently being assessed experimentally.