To understand Islam, you must understand the harsh circumstances into which the religion was born. The Arabian Peninsula at the time of Muhammad (b.570 AD) was a barren and desolate region with a scorching sun and oppressive heat by day, and a chilling cold at night. There was little vegetative growth, and the nomadic inhabitants lived between jagged rocks and shifting sand dunes.
While Europe and much of the Middle East was transitioning from the Roman to the Byzantine Empire, with roads, irrigation canals, aqueducts, and a culture that included philosophical discourse and theater, the Arabians lived short and brutal lives in warring tribes with little to offer the rest of the world beyond their own harsh existence.
Muhammad's failure to leave a clear successor resulted in a deep schism that quickly devolved into violence and persists to this day as the Sunni/Shia conflict. His own family fell apart and literally went to war with each other in the first few years. Thousands of Muslims were killed fighting each other in a battle between Muhammad's favorite wife, Aisha, and his adopted son, Ali.
Infidels fared no better. Through Muhammad's teachings and example, his followers viewed worldly life as a constant physical battle between the House of Peace (Dar al-Salaam) and the House of War (Dar al-Harb). Muslims are instructed to invite their enemies to either embrace Islam, pay jizya (protection money), or die.
Over the next fourteen centuries, the bloody legacy of this extraordinary individual would be a constant challenge to those living on the borders of the Islam’s political power. The violence that Muslim armies would visit on people across North Africa, the Middle East, Europe and into Asia as far as the Indian subcontinent is a tribute to a founder who condoned subjugation, violation, murder and forced conversion in the cause of spreading the rule of his religion.
In Muhammad's words: "I have been ordered to fight the people till they say: 'None has the right to be worshipped but Allah.' And if they say so, pray like our prayers, face our Qibla and slaughter as we slaughter, then their blood and property will be sacred to us and we will not interfere with them, " (Bukhari 8:387)
It is certainly the basis not just for modern day terror campaigns against Western infidels (and Hindus and Buddhists) but also the broad apathy that Muslims across the world have to the violence, which is an obvious enabler.
As Indonesian cleric, Abu Bakar Bashir recently put it, "If the West wants to have peace, then they have to accept Islamic rule."