The decision to wage war originally rested in the hands of the direct descendants of Muhammed . This worked until a rupture occured after the murder of the third Caliph,‘Ali . The Battle of Karbala brought a final rupture with the Sunni following the caliph and the Shi’a waiting for the return of the hidden Imam. For the Sunnis religious and political authority are united; for Shi’ites it is divided; religious authority lies with the imam and only defensive Jihad is possible.'¢
Originally decisions made about war and conquest were intended primarily to deal with polytheists; when many lands with monotheistic religions were rapidly conquered, concessions were made to people of the book, i.e. Jews , Christians , and Zoroastrians . Their followers were understood as monotheists of a less desirable form which could be tolerated in an otherwise all Islamic society. This also proved a useful way of integrating and using the skills of these minority groups, a necessity as the conquerors had not been prepared for the rapid conquest of so many lands. Such believers were relegated to second class citizenship and remitted a tributary tax for the privilege of existing under Islamic sovereignty.
Jihad carried missionary fervor from the Arabian desert into Asia and to the boundaries of Europe . It led to a millennia of bitter conflict in which Jews were generally bi-standers, suffered the outrages of war, and were then given subsidiary status in peace time. When the passions of jihad were exhausted, better conditions could emerge as in the Golden Age in Spain (1280-1340) and occasionally later. Within this framework war was, nevertheless, understood as basically evil. It was tolerated only in the service of bringing people to Islam . Holy war was one of the acts of piety enjoined upon Muslims ; it followed faith, prayer, fasting, and pil grimage, all essential acts of piety. War was permitted to be destructive force which included laying waste date palm groves, vineyards, etc."
: Waras a holy enterprise whose goal was peace was justified by virtually all the great Islamic theologians, both Sunni and Shi’ite . As Islam is a judicial system different theories lead to different practical details. Religious and political leadership were theoretically united, however, practical adjustments were made throughout the centuries. The tensions created through differing decisions by various leaders