If Steven Spielberg had made a fictional movie about the psychological disintegration of a revenge assassin, that would have been fine. Instead, he decided to call this fiction "Munich" and root it in a historical event: the 1972 massacre by Palestinian terrorists of 11 Israeli athletes at the Olympic Games. Once you've done that — evoked the killing of innocents who, but for Palestinian murderers, would today be not much older than Spielberg himself — you have an obligation to get the story right and not to use the victims as props for any political agenda, let alone for the political agenda of those who killed them.
The only true part of the story is the few minutes spent on the massacre. The rest is invention, as Spielberg delicately puts it in the opening credits, "inspired by real events."
By real events? Rubbish. Inspired by Tony Kushner's belief (he co-wrote the screenplay) that the founding of Israel was a "historical, moral, political calamity" for the Jewish people.