== Needs sourcing == 
 The article says:"Some critics believe this event set a disturbing precedent in Islamic law that established the right of Muslim captors to show no mercy to captives of war." 

 This needs to be sourced. In fact, it goes against Peters statement that: 

 Not only did the Jews of Medina reject Muhammad's prophetic claims; they began to connive with his enemies in Mecca to overthrown him. Muhammad's own reaction was determined and progressively more violent. As the Prophets' political strength in the oasis grew, the Jewish tribes of Medina were first banished, then taken and enslaved, and finally executed on the spot. This quite extraordinary behavior is matched by nothing in the Quran, and is quite at odds with Muhammad's treatment of the Jews he encountered outside Medina. We must think then that his action was essentially political, that it was prompted by behavior that he read as treasonous and not some transgressions of the law of God. 

 So, please source this.