The theoretical model presented in this thesis purports to explain the American diplomatic strategy toward Iran in the dispute over the latter’s nuclear program. The aim of the dissertation is two-fold. First, I deduce a provisional theoretical model of diplomatic strategies in conflict situations in which the perspective of the stronger power is assumed. Second, I apply the model to the conflict under study. The model fuses two concepts from cognitive studies within International Relations (IR). First, drawing on work on operational codes, I have developed the concept of the key strategic belief. Second, building on image theoretical studies, I have designed the concept the image of the adversary. The former may be conceived as a more general belief about the nature of states and the function of power, whereas the latter involves assumptions about the character of the relevant opponent. The issue of contention between the two states as defined here concerns the uranium enrichment process, which may produce fuel for nuclear reactors, but could also provide highly enriched uranium (HEU), which is fissile material for nuclear weapons. In this conflict situation, where Iran continues its enrichment activities in spite of American demands that Iran is to suspend its enrichment program, there exists an incompatibility between the two actors’ goals. From the vantage point of the stronger power, a wide range of foreign policy tools are available. The working hypothesis is that the key strategic belief and the image of the adversary in combination help the policymaker calibrate the diplomatic strategy. The analysis of the key strategic belief concluded that the first Bush administration held the bandwagon proposition as a valid hypothesis as to how states react to threats. Measured through the standing of the Bush doctrine the analysis argues that during the period under study the belief in the principles of balancing gained strength to the detriment of the bandwagon hypothesis. As for the administrations’ image of Iran, the analysis suggested that the image of Iran as an essentially expansionist power had been sustained by both administrations, although that perception had weakened somewhat. The diplomatic strategy evolved as the nuclear issue received more attention. The first Bush administration met Iran’s defiance with an aggressive posture which downplayed the possibility of accommodative measures. As the nuclear issue gained importance, the stick remained dominant, although the US increasingly offered limited concessions. The US has presented Iran with a choice between two outcomes; one, agree to the suspension of the enrichment program and receive the concessions stipulated, or two, remain defiant and reap increasingly stiffer punitive measures. It seems apt to portray the American strategy as a mixed approach in which minor concessions are coupled with possible major repercussions.