To what extent are the sectarian identities in the Middle East propelled by the dualistic religious differences between the Sunnis and Shi’a?

Question: To what extent are the sectarian identities in the Middle East propelled by the dualistic religious differences between the Sunnis and Shi’a?

Arguments:

1. The White Revolution reforms formulated during the reign of Shah introduced political realism and started the abolishment of religious ruling, increasing the rift and the dualistic war between the Shi’a and Sunnis.
2. Add an argument about the 1973 oil crisis.
3. Sectarian identities in the Middle East, specifically in Iran, and the dualistic war of the Shi’a and Sunnis, are rooted in the introduction of the Iranian religious regime in 1979, which was characterized by governing based on religion as opposed to the political policies and modern democratic appeals.
4. The invasion of Iraq in 2003 and the overthrow of the Saddam Hussein’s Sunni/Secular regime upended the sectarian balance of power in the region in Iran’s favor.