2.5 Million Pilgrims Descend on Mecca for the Hajj

At least once in the lifetime of every able-bodied believer, Islam requires a pilgrimage to Mecca. Between the seventh and thirteenth days of the twelfth month of the Islamic calendar, millions of people unite in religious solidarity. This year's observance is already under way. Radwan Masmoudi, who performed his "Hajj" in December of 2007, is founder and president of the Center for the Study of Islam and Democracy, a think-tank in Washington, DC.