Reply #16: More spoilers.

[Orsino]

1. I'm guessing that this was a relic of Manhattan's humanity. He still felt some patriotic obligation to win a war, and might even have done the math: a relatively few quick deaths could destroy the Communists' will to fight and end the conflict sooner. There's also the thought that the war might have looked more winnable when he joined up then it turned out to be in practice, and that Manhattan was simply following through, with some reluctance. Nixon, we assume, was not revealed in the world of Watchmen (the Comedian did away with Woodward and Bernstein, it is hinted) as the pathetic, corrupt creature we know.

2. We know that conservatism is never happy. It runs on fear and ignorance, and so always needs an enemy. It's quick to blame its own victims. The uncompromising Rorschach can't be everywhere at once, so there is always more filth around the corner--which in turn hardens his resolve.

3. I don't see it as a god allegory so much as a map of human failure; this incident was a glimpse of an earlier stage of his detachment from mortal affairs. The accident that expanded his awareness also made him less able to care about us. It's a paradox that can only be resolved by Manhattan's departure at the end of the story.

4. I believe that the reactors were exploding all over the world, and Ozymandias was careful to leave Manhattan's fingerprints, so to speak, on the disasters. Oz "saved" the world by giving it a single enemy, one they had already been coached into hating (over the cancer thing).