Unfortunately, the Jews were unaware that peace talks can only be conducted with Muslims when they find themselves to be weaker than the disbelievers (ie., 'reloading'). However, Muslims should never seek diplomacy if they are superior in strength to their enemies - and they are to continue fighting until an Islamic theocracy is established.
As the old saying goes, 'those who do not learn the lessons of history are doomed to repeat it'.
Hopefully, non-Muslims will learn from this massacre and avoid repeating any similar blunders in the future.
The assassination of another Jewish leader in Kheibar occurred a short while later. Muhammad sent a hand-picked "commando unit" of thirty killers to Kheibar disguised as an official diplomatic approach to the Jews there. The Muslims negotiated with their leader, Usayr ibn Razim, and convinced him to go to Medina to negotiate with Muhammad. The Muslims offered to guarantee his safety with their own escort of thirty men. Among Arabs, nothing is more valued than a man's word, his pledge of safety and protection, so ibn Razim felt safe. Somewhere on the road to Medina, however, the Muslims fell upon the Jews and killed them all.
When the leader of the commandos returned to Medina he was met by Muhammad, who congratulated him on his work. Muhammad was earning an ability for his ruthlessness and an ability to kill at a distance just as the size of his army was increasing and he was becoming better able to support his followers economically. The message to his opponents outside the cities was that they, too, were not safe as long as they failed to join him.
Muhammad: Islam's first great general, p 129