Islam is now a truly global religious tradition. Approximately 1.57 billion Muslims live worldwide, on every continent and in most countries. In very general terms, about a third of the total live in the Middle East and North Africa. Several major ethno-lin-guistic groups are represented there, including Arabs, Turks, Persians, and Berbers. Many people associate Islam with Arabs even though they are now a relatively small minority of the global population. Another third live in central and southern Asia, including the southern republics of the former Soviet Union, Western China, India, Pakistan, and Bangladesh. Pakistan is the most important modern example of a nation-state established as a Muslim land. Another third are in sub-Saharan Africa, Indonesia, and in smaller concentrations in several dozen other countries. Indonesia boasts the single largest national population of Muslims, approaching two hundred million. At over a hundred million, India is home to the world’s largest minority Muslim population. Muslims number from six to eight million in the United States.

It may also be helpful to think in terms of religio-cultural spheres, defined by key language groups, in which Islam has been a particularly important influence. The Arabicate sphere, for example, includes all those areas in which Arabic has been the dominant vehicle of Islamic expression, namely, the central Middle East, north Africa, and east Africa. The Persianate sphere consists of Iran, Afghanistan, and all of southern Asia. Within the Malayo-Polynesian sphere are Malaysia, Indonesia, and the Philippines. Central Asia, including western China, and present-day Turkey and the Balkans comprise the Turkic sphere. Last but not least is the sub-Saharan sphere, in which Nigeria and other west African nations are most significant.