The Middle East is experiencing a new era involving a cold war between the theocratic Shi'i state of Iran and its rival Saudi Arabia, a theocratic Sunni state, both considering themselves the leader of the Muslim world. These countries have been rivals for decades, and the consequences of this rivalry have been shaping the Middle East since 2011. This research intends to review the main issues over the last four decades involved in the rivalry between Iran and Saudi Arabia. By examining the main issues involved in this rivalry, the research attempts to discover whether the animosity between Tehran and Riyadh following the Arab Spring is based on both sides' effort to strengthen their proxies by using the Arab Spring's flames. The research suggests a new conceptualization of how religion -Sunna and Shi'a -represents the historical clash on the question of who should have, must have, and who has the historical right to lead the Islamic world. This clash originated mainly from one focal base, Islam, yet it represents a separation between 'theo' -the Islamic religion, and 'civilio' -ethnic rivalry, or Arab vs. Persian culture. The objective of the study is to offer a practical solution to enable the two rivals to coexist for the region's greater good, even if they cannot fully resolve their rivalry.