This thesis deals with the topic of the conflict between the US and Iran over Iranian nuclear program and the possibility of resolving it by negotiating a mutually acceptable comprehensive agreement. The aim of this thesis is to analyze whether a zone of possible agreement between the US and Iran on the nuclear issue exists; and if it does, what range of possible agreements falls within it. In order to determine whether a ZOPA exists, the thesis utilizes the negotiation analytic approach, which establishes the elements of the analysis - the parties' underlying interests, their alternatives to a negotiated agreement, barriers to agreement and deal design. By putting the setup elements into a graphical framework representing the negotiation, the analysis finds that a zone of possible agreement between the US and Iran over Iran's nuclear program exists and therefore, a comprehensive deal is possible. However, the existence of major potential barriers to agreement, such as powerful domestic opponents to an agreement on both sides, complicates the negotiating process. The findings of the analysis indicate that to overcome these barriers and reach a mutually acceptable deal, both sides have to retreat from their fixation on maximalist bargaining positions and instead focus on their core underlying...