It's Not About Us - By Christian Caryl

Most Westerners have heard that there's a difference between Sunnis and Shiites, but there are very few of us who can say what it is. I hate to be the one to bring this up, but it's probably time to start getting educated. Like it or not, the 21st century will be dominated by the political reverberations of the rivalry within Islam. The so-called "war on terror" pales in comparison.

If anyone had any doubt about this, just take a look at the recent headlines. Earlier this week, 89 Shiite Hazaras were killed in a bombing in the city of Quetta in Pakistan. Pakistani's 30 million Shiites (the second-largest population in the world, right after Iran) are increasing targets of persecution by the country's Sunni majority. Another attack five weeks earlier killed 100 other Shiites in the same city.

The very same day as the Quetta bombing, six car bombs and three roadside explosions killed 21 people in Baghdad. All of the attacks targeted Shiite neighborhoods. Some 60 percent of Iraqis are Shiites, but that only seems to fuel the sectarian violence there, which has been going on now for almost seven years. Most of the attacks have been staged by terrorist groups like al Qaeda, who regard Shiites as heretics and claim to speak for the Sunni minority that has dominated the political system for much of the country's modern history. Many Sunni Iraqis still haven't reconciled themselves to being ruled by Shiites, people they often don't consider to be "real" Muslims. Sunnis are now vowing to organize politically to defend their claims.

The Shiite-Sunni split is also a major factor in Syria's continuing civil war. President Bashar al-Assad belongs to the Alawite sect, which practices a distinct version of Islam that is close to Shiism. Even though the Alawites amount to a mere 15 percent of the population, they have long been a pillar of Assad family rule. This sectarian factor has reinforced the Assad regime's close alliance with the Shiite regime in Tehran -- and also fuels the hatred felt by members of the conservative Sunni majority towards the regime in Damascus.

So why should non-Muslims care? Because the dynamic of mutual hatred and distrust between the two camps shows every sign of intensifying -- and given that 1 billion believers are caught up within this theological and demographical battle, the rest of us are bound to feel the shock waves. (The United States, for example, continues to prop up the Sunni royal families in Bahrain and Saudi Arabia, both of which are still suppressing lingering Shiite rebellions by the most brutal of means. And let's not forget Iran's efforts to build the first Shiite nuclear bomb.)

The differences between Shiites and Sunnis go back almost to the dawn of Islam itself. The crucial distinction has to do with the nature of religious authority. Sunnis essentially believed that the leader of the Muslim community, the caliph, should be chosen from among its members. (In the early days, they were usually selected from the original group of companions of the Prophet Mohammed.) Shiites were those who insisted that the leader could only come from the line of Mohammed's direct descendants, and they soon came to challenge the caliphs' right to leadership. The dispute took a fateful turn for the worse when Hussein ibn Ali, the Shiites' leader and the Prophet's grandson, refused to pledge allegiance to the caliph Yazid, and died at the hand of the caliph's troops in the battle of Karbala in 680 -- igniting an intensely emotional narrative of injustice and martyrdom that still infuses Shiite thinking today. (Take a look at this video for a taste.)