Even before STID, Berman Era Trek had turned Khan into a Dictator on par with Hitler, a man so feared that Earth and Starfleet was terrified of there ever being another one like him. That's not the work of a skilled diplomat, that's someone that was racking and stacking bodies.
Well it was called the Eugenics Wars
, and it's unmistakable that Khan and his fellow tyrants didn't play nicely together and caused a lot of death in the process. Obviously nobody would want the return of that. The TOS assessment of Khan as a ruler is obviously not referring to the whole aspect of the world being at war but to his characteristics as a potentate within his own borders.
If the idea of departing from that was invented by some iteration of Berman Era Trek, again I don't think that's necessarily a huge endorsement of it (quintuply not, for my taste, if the Berman Era Trek you have in mind is Enterprise, with apologies to any fans of such here present)... though TBH I mostly remember the never-seen "Li Kuan" being pressed into service as Obligatory Future Dictator on lists involving Hitler.