Counterproliferation strategies should be informed by an objective understanding of the motivations of proliferating states. This report applies an exploratory methodology for developing alternative models of the reasoning of national leaders considering acquisition of weapons of mass destruction. It can be used for analysis or as a mechanism for group discussion. It assumes that the leaders in question strive for rational decisionmaking by considering the most-likely, best-case, and worst-case outcomes of various options. That is, they reflect at least limited rationality by considering a range of options and by looking at the upside and downside of those options, as well as best-estimate outcomes. The models allow ample opportunity for "errors," however, by recognizing problems associated with recognizing and evaluating options. They also recognize that psychological and organizational factors can introduce biases and other types of misjudgment. The approach draws on Davis-Arquilla methods developed earlier for use in crisis work.