The Gulf-Iranian relation was and still is the most controversial issue. This controversy intensified after signing the Nuclear deal between Iran and western countries on the 14th of July 2015. Although the deal has closed the Iranian nuclear file (relatively and temporarily), yet it has not ended the concerns of the GCC states regarding current and future Iranian policies, not only towards the GCC countries but also towards the wider region especially since Iranian regional policies have become more intrusive than ever before. This is confirmed by the Iranian attacks in January 2016 on the headquarters of Saudi Arabia’s diplomatic mission in Tehran and on the Consulate in Mashhad to protest against judicial rulings in Saudi Arabia regarding individuals linked to terrorism. Such events confirm day after day that the GCC countries are not only facing state policies, but they are facing the risk of an “Iran’s regional project”. This projects aims to make Iran the leading player, with no regard to whether this represents a threat to its neighbors or whether this is consistent with the principles of international relations including good neighborliness and noninterference in the internal affairs of neighboring countries. These two principles are among the principles that were the basis for the foundation of regional and international organizations and were fundamental pillars for the sovereignty and independence of countries. Based on the above, this study aims to answer four questions: 1. What are the characteristics of the Iranian regional project? 2. How does the Iranian nuclear deal effect Iran’s regional policies in terms of content and orientation? 3. Did the Iranian attacks on the Saudi diplomatic headquarters in Iran initiate or reveal the strained Iranian-Saudi relations, and how can the Iranian policies be explained? 4. What is the proposed Gulf strategy to counter Iran’s current and future policies?