Tariq Ali in Counterpunch:
Historians of Islam, following Muhammad’s lead, would come to refer to the pre-Islamic period as the jahiliyya (‘the time of ignorance’), but the influence of its traditions should not be underestimated. For the pre-Islamic tribes, the past was the preserve of poets, who also served as historians, blending myth and fact in odes designed to heighten tribal feeling. The future was considered irrelevant, the present all-important. One reason for the tribes’ inability to unite was that the profusion of their gods and goddesses helped to perpetuate divisions and disputes whose real origins often lay in commercial rivalries. Muhammad fully understood this world. He belonged to the Quraysh, a tribe that prided itself on its genealogy and claimed descent from Ishmael. Before his marriage, he had worked as one of Khadija’s employees on a merchant caravan. He travelled a great deal in the region, coming into contact with Christians, Jews, Magians and pagans of every stripe. He would have had dealings with two important neighbours: Byzantine Christians and the fire-worshipping Zoroastrians of Persia. Muhammad’s spiritual drive was fuelled by socio-economic ambitions: by the need to strengthen the commercial standing of the Arabs, and to impose a set of common rules. He envisioned a tribal confederation united by common goals and loyal to a single faith which, of necessity, had to be new and universal. Islam was the cement he used to unite the Arab tribes; commerce was to be the only noble occupation.
…The military successes of the first Muslim armies were remarkable. The speed of their advance startled the Mediterranean world, and the contrast with early Christianity could not have been more pronounced. Within twenty years of Muhammad’s death in 632, his followers had laid the foundations of the first Islamic empire in the Fertile Crescent. Impressed by these successes, whole tribes embraced the new religion. Mosques began to appear in the desert, and the army expanded. Its swift triumphs were seen as a sign that Allah was both omnipotent and on the side of the Believers. These victories were no doubt possible only because the Persian and Byzantine Empires had been engaged for almost a hundred years in a war that had enfeebled both sides, alienated their populations and created an opening for the new conquerors. Syria and Egypt were part of the Byzantine Empire; Iraq was ruled by Sassanid Persia. All three now fell to the might and fervour of a unified tribal force.
More here.