The innovation in The Authority wasn't in the other titles you mention, Dave. It was the bald fact that if you're altruistically minded and have incomparable superpowers, how can you sit back and do nothing while innocents are murdered. Millar's run on the Authority begings with the team dumping the Indonesian president BJ Habibie into a truckful of corpses in East Timor, with surivors advancing on him with machetes, following the Indonesian-sponsored militia genocide of Timorese. It was Millar's contemporaneous act of revulsion enacted through the characters: they shared his revulsion and acted on it.
The Authority later intervene in Chechnya and, off-panel, Tibet. Its not a utopian change like Miracleman or Red Son - its acting decisively on conscience. In Watchmen, Dr Manhattan was so detached from his humanity that he regarded human life, even after his epiphany, as a terribly interesting science experiment. There was never altruism in his actions. And Stan Lee never had Spider-man assassinate Pol Pot or Mao Zedong, although in a real world a man with a conscience and his powers should certainly have at least contemplated it.
If there is a precedent, its WW2 writers of superheroes, who regularly through patriotism fought Nazis and Japanese. Starman recaptured the Aleytians from the Japanese, even though this didn't obviously happen in history.
Millar asks, if you had a power ring or whatever, would you sit around while people are hacked or bombed to death? And if you wouldn't, what's the vastly less-self interested Justice League or Avengers doing in their mansions or lunar headquarters doing?
And the answer is too difficult for mainstream comics to address.
