Diplomatic relations between states do sometimes go backwards in their process and development. One of these cases is the United States-Iranian diplomatic relation which has gone backwards in its development. This study is based on two main different theories, the Habermasian model and the Hobbesian trap. This, with the purpose to understand how lack of consensus and presence of fear are the reasons for the disruption of the United States-Iranian relations' development. The results have shown different directions, concerning the theories, in which they can affect the countries bilateral relations. The main reasons for the disruption of the relations, from the Iranians' perspective, are due to their interpretive concerning United States willingness to be the leader of the international community. From the Americans' perspective, the disruptions are due to their interpretive concerning Iranians' attachment to their own nuclear programme. The conclusion of this study shows how lack of consensus and presence of fear has prevented the United States-Iranian diplomatic relation to develop, and that the theories potency of strength, therefore, is high.