On Sunday, January 3, Saudi Arabia cut diplomatic ties with Iran, an escalation of the decades-long tensions between the Sunni-led Saudi kingdom and the Shia-dominated Islamic Republic of Iran. The precipitating event for this most recent flare-up was the Saudi execution of a prominent Shia cleric, Nimr Bakr al-Nimr, in Saudi Arabia. Tensions, however, have been simmering for some time, especially in the wake of Iran’s and Saudi Arabia’s mutual involvement in the civil war in Yemen, Shia protests in Bahrain, and Iran’s significant involvement in Iraq since 2003.

Saudi diplomats had already abandoned Iran on Sunday, after mobs descended on Saudi diplomatic facilities in Tehran on Saturday, setting fire to the Saudi embassy and other facilities there. Nimr was a vocal critic of the Saudi royal family, according to the Washington Post, and was executed for political activism and anti-government activities, as well as for “threatening the security” of the kingdom. To most observers, he appeared to be nothing more than a pro-democracy advocate, and not a terrorist figure of any sort.

When one attempts to view the Saudi-Iran conflict from a detached 30,000 feet, through the lens of both regional and religious history, one is able to discern religious/sectarian and geopolitical dimensions underlying the tensions. First, from a theological perspective, the majority Sunni and minority Shia blocks of Islam have long been at odds, with Sunnis viewing Shias as dangerous apostates of the faith. From the Shia perspective, theirs is the true post-Muhammad lineage of Islam. The Shias see themselves as victims of persecution for their faith, following their split from the Sunni sect after the death of the prophet.

Geopolitically, more recognizable national security issues come to the fore. Saudi Arabia views Iran as a regional rival, vying for a increased influence in southwest Asia through its proxies and allies, including co-religionists, in Lebanon, Syria, Yemen, Iraq, and Bahrain. Iran’s influence in the region has grown significantly since the 2003 invasion of Iraq, and following its recent nuclear accord with America. Iran sees itself as a regional force that should have a significant say in regional political issues. Saudi Arabia sees Iran as a dangerous rival, seeking to undermine Saudi security efforts and supporting Shia minorities in Saudi Arabia, as well as Shia populations in Bahrain and Yemen. Geopolitically, it is a classic case of two states vying for increased power relative to the other.