The Gemara’s narrative of Kamtza and Bar Kamtza is told as the cause of the destruction of Jerusalem. But the story does not blame the host who insulted the guest, and does not blame the guest who took revenge. It blames the Sages who were present and did not protest.
Why? This essay reads the narrative as a deliberate inversion of where the reader expects the moral weight to fall — and argues that the Gemara is making a structural point about communal responsibility that the surface plot conceals.