The Washington Post busts McCain on his claims about past presidential meetings with foreign enemies. His misunderstanding of the Reagan-Gorby meeting is particularly bad.
That said, I think China and the USSR--giant nuclear-armed powers--are a somewhat different deal than a rogue state like Iran. Iran has no comparable base of foreign allies and this seems like a case where isolation and ostracism--at the presidential level, which is different from less public forms of diplomacy--could make more sense. That question is admittedly a bit out of my element--though I'm still guessing, until I see contrary evidence, that it's what most Americans believe.