What really happened to the Bani Qurayza Jews? Were they traitors or they were betrayed? Why did Prophet Muhammad massacre the Bani Qurayza Jews in Arabia?

Muhammad was trying to get the Jews in Arabia peninsula to believe him as a prophet and accept Islam , but no matter how had he tried the Jews couldn't believe him. This lead to several battles between Prophet Muhammad and the Jews. The battle of Trench, the Battle of Badr, The battle of The Battle of Al-Khandaq.
No matter how hard Mohammed tried to convince them that he is a prophet he just couldn't. There was a time he even barged into a Jewish Synagogue in Yathrib (Al-Madina Al-Munawwarah) and said that if only twelve Jews would believe in him then Allah would spare them his wrath Musnad Ahmad - 23464

Quraysh and Ghatfan, encouraged by the Bani Al-Nadheer Jews who were exiled by Muhammad, wanted to eliminate Mohammed once and for all. They gathered up a great army and put Yathrib under siege [Saheeh Bukhari - 4103].
Mohammed , based on a suggestion by Salman Al-Farisi, dug a trench around Yathrib [Saheeh Bukhari - 2837], except for the Bani Quraytha side that is, because they had great fortresses and it would be practically impossible for the Pagan Arabs to get through their fortresses unless Bani Quraytha allowed it.

Now since Mohammed and Bani Quraytha had a treaty, Mohammed had nothing to fear [Saheeh Muslim - 1766 and Sunan Abi Dawood - 3004]. Therefore all was set.

Full details on the video...

https://www.youtube.com/watch?v=SBkNA2XvqAY