In the weeks leading up to November 21, millions of Shiite Muslims will flock to the southern Iraqi city of Karbala for the world’s largest annual pilgrimage. Although the Arba’een pilgrimage has recently swelled to about ten times the size of the Hajj, it remains virtually unknown in the West. Pilgrims from across the world perform this ziyara—or visit to the shrine of the Prophet Muhammad’s grandson, Imam Hussein—on foot to mark 40 days after his martyrdom. The event commemorates a central moment in the Sunni-Shiite divide and was largely restricted during the rule of Saddam Hussein, who saw the massive physical mobilization of Shiites as an implicit threat to his regime.
Since Saddam’s fall, participation in such religious festivals has risen steeply. The new Iraqi government opened the borders to Shiites from around the world, and in 2004, over two million pilgrims, including 100,000 Iranians, went to Karbala for Arba’een. Ten years later, and despite the Islamic State (ISIS) takeover of Mosul, the pilgrimage in the fall of 2014 welcomed a reported 17 million pilgrims, including over a million Iranians who were able to enter as a result of the lifting of visa restrictions for the pilgrimage. We used the unique opportunity afforded by last year’s Arba’een pilgrimage, which attracted a reported 22 million pilgrims, to survey over 4,000 observant men and women from two of the largest and most influential Shiite countries: Iran and Iraq.
The survey covered a vast range of topics—from religion and gender to Western intervention and Iran’s nuclear agreement—at a pivotal time, when the United States is fighting ISIS in Iraq and Syria, working to enforce the nuclear agreement with Iran, and combating intense sectarian conflict in Syria and Yemen. We found significant transnational allegiances among these religious Shiites, as well as pragmatism about the benefits of working with the United States to promote a more stable and prosperous Middle East.
Roughly 20 percent of the world’s Muslims are Shiite, and