The role of the U.S. grand strategy in the security strategies of regional powers: The Iran-Saudi Arabia rivalry (2010-2020)

This study examines the growing rivalry and conflict between Iran and Saudi Arabia in the post-2010 period. The main aim of the study is to reveal that the reasons behind the rivalry between these two countries within the framework of changing grand strategy of the United States and by the perspective of structural realist theory. In this context, the thesis seeks to answer the following question: why does the power vacuum in a region, which is the result of the changes of sole superpower's grand strategy towards this region, intensify competition and conflict between any two of the regional actors? Within the framework of this approach, the study argues that the regional power vacuum in the Middle East pushes actors into a power struggle. Two dynamics explain why this struggle is more pronounced between Iran and Saudi Arabia. The first is the threat perceptions of these two countries towards each other. The second is the direct impact of the US grand strategy on these countries. Testing the hypotheses developed in this context through the relations between Iran and Saudi Arabia, the study provides a generalizable framework for the behavioral patterns and security strategies of regional actors.