Hi, I wrote the chapter on utilitarianism and deontology in Watchmen and Philosophy, and I went out of my way to avoid making the mistake that EmPiiRe x describes.
EmPiiRe x is absolutely right, Veidt is not a utilitarian, he uses utilitarian ethics to rationalize his quest for power. Similarly, Rorschach is not a deontologist. He uses deontology to rationalize his actions.
Here's what I said in the book.
So neither consequentialism nor deontology comes off well in Watchmen. The characters use the ideas as thin rationalizations for corrupt behavior, and at least in the case of utilitarianism the ideas themselves are shown to be flawed. But critiquing consequentialism and deontology is not the main goal for Moore and Gibbons. Their deepest concern is obviously expressed in the aphorism which gives the comic its name and which appears in fragmentary form throughout the book: “Who watches the watchmen?”
Then at the end I wrote
Rorschach and Ozymandias are important because we see in them that anyone can be corrupted. Leftist or rightist political views are really of little consequence, because they are merely ways that the powerful rationalize what they are doing. Consequentialism and deontology are merely further rationalizations of these ruling ideologies. It is thus not surprising that neither view really gets a fair shake in Watchmen. Moore and Gibbons aren’t interested in whether the views can be tinkered with to the point that they are a reasonable guide to behavior, because that is not how these ideologies function in the real world.
I hope that clarifies things.