1) Islam spread rapidly for several reasons, including that Arab armies were unified in their beliefs, Muslim warriors were promised paradise for fighting holy wars, and existing empires accepted Islam's messages of equality.
2) By 732 AD, just over a century after Muhammad's death, Islam had spread from the Indus River to the Atlantic Ocean.
3) In the early 1900s, the West became interested in Middle Eastern affairs due to the region's falling behind in technology and the growing importance of oil, which influenced Western foreign policy.