The only fallacy of the comparison? The Jewish state hasn't gotten around to committing the acts that their leaders wish to commit.
Even if that were true, that's a pretty big distinction Cyclo. Many people throughout history have had ugly wishes and expression but Nazis remain the penultimate example of evil in most people's minds not because of the wishes some of them may have had but for the realization of their atrocities on the scale that they reached.
It's a cheap and easy argument, but it's a vacuous one that diminishes the horror that Nazis inflicted. Hitler and Nazis are overused superlatives that are not proportionally appropriate to describe Israel and combined with the offense it carries for Jews (for obvious historical reasons) it's the kind of argument that makes it harder to reasonably criticize Israel.