Even if it was true, there is no inverse correlation between IQ and cruelty. Some of the world’s worst monsters were high IQ.
True. Psychopaths are often high IQ and cruel. But how many of them were involved in intellectual debates with the world opposing them? Having sound cognitive function should allow you to discern between right and wrong, especially in an environment where other intellectuals have proven you wrong on an inductive and logical basis. At the point where we are right now wrt defending Israel, it's no longer a function of intellect but of pure brainwashing of the highest degree. Take the example of Ilan Pappe, for example: an Israeli intellectual who became anti-Zionist.
Brainwashing is unnecessary; this is what they have always wanted. Unprovoked aggression and the desire to dominate others is cultural.
If it was unnecessary, all the Jews would be supporting Israel. Most Jews are anti-Israel, anti-Zionist, and some are amongst the staunchest of critics (i.e. Chomsky, Finklestein, Pappe). The Zionist brainwashing didn't work on them.