The problem with a multi-species political organization like the Federation is that eventually someone has to rise to the top. One culture is bound to gain more influence over the others. As much as each species is to be accorded equal representation and regard within the Federation, if we look at the TOS episode Journey to Babel, the various representatives of the different races were prone to infighting, bickering and all sorts of abhorrent behaviour that made them appear reprehensible. It was Terran diplomacy and behavioural superiority that kept their base attitudes in check. Even in Star Trek: Enterprise, Terrans appear to be the noble underdog and the intellectually and technologically advanced Vulcans who welcomed Earth to the stars are presented as a bullying and overbearing race. Its almost propagand-ish in that despite this bullying and the Terran lack of experience, the sense of racial and moral superiority still manages to propel humanity into situations it isnt prepared for, despite Vulcan intervention or admonitions. The Terran attitude in this case is one that borders on racial superiority. While Star Trek III is to exist in a time frame beyond the years of these episodes, it would be interesting to see if Earth values supersede those of the Federation allies. Perhaps this is something that could be explored further should Earth submerge its identity and values in preserving the integrity of the Federation or will Terran stubbornness overwhelm common sense?