Before I move on with the actual review of the film, let me state a few things. One, I will try to keep this review free of major spoilers, but a few minor ones may slip out from time to time, so be warned. Two, this movie involves several political themes. Discuss them if you'd like, but keep them relevant to the movie itself. Thanks.
Hard-line Republicans will hate this movie. The mentions of "the former United States" and "the war that America started" are not major themes of the movie, but are thrown in to paint it with a modern splash of color that ultimately removes us from being able to escape into fantasy. The directors make it quite clear that they do not want this movie to be an escape, but a warning of how things could become.
That said, I could not personally suspend disbelief to that extent. The level of political discourse that exists in our world, and especially in Britain, makes it seem impossible to reach this extent of cruelty. But then, it's not as if the hard left will be pleased with this movie either; it runs the dangerous risk of associating their current views with the eventual need for terrorism and the killing of innocents, so they're left with little choice but to approach any level of political enthusiasm cautiously.
In V for Vendetta, years of war and biological viral weapons have led to the creation of a new level in the British government: High Chancellor. In this world, obviously inspired by Orwell's 1984, curfews are imposed and the government controls everything from the sale of foods to what is shown in the media outlets. Standing against all of this is V, a mysterious man wearing a Guy Fawkes mask, who spreads political dissent through media channels as readily as he spreads explosives. He's also quite handy with a knife.
And since it focuses on so many hot-button issues, this is only in part a "comic book" movie. While the action scenes are done very much in an action-oriented style (courtesy of the Wachowski brothers of Matrix fame), all that comes between those scenes are more in the style of a drama or psychological thriller. The abject creepiness of V's mask haunts the entire film, but the audience eventually learns to look past it, to see it as a part of his character, and even a necessary role. As he reminds us, the face behind the mask does not matter nearly as much as the idea behind it.
And what are these ideas? That the government should be afraid of its people, not the other way around. That extreme measures must be taken. That ideas are invincible. While all of these are noble, the movie sometimes gets too pleased with its own superior sense of morality and overstates its points. I agreed with the points at face-value, but the film for some reason seemed to feel the need to hammer away at them, as if it had something to prove. And perhaps, to some audiences, it does; but I doubt those audiences will like the movie in any case.
Given that it is, in fact, a superhero movie, a hero must exist. The hero is V, of course, but in a more poignant way (and one of the more subtle bits of symbolism in the film), the hero is society. The hero is each and every individual that has the courage to say what they think regardless of the risk it may put them at. My particular screening involved a trailer for Superman Returns, in which Jor-El's haunting voice tells us, "They can be a great people... if they wish to be. They only lack the light to show the way." In this, it struck me that V for Vendetta is almost the mirror image of Superman's themes. The real inspiration behind the character is in his ability to rally the people to do great things; the difference is that while Superman encourages being kind to your fellow man, V encourages placing explosives on historic landmarks.
In all, this movie will leave you with what you went in with. If you expect a satisfying superhero movie, you will get it, though a tad different from your usual Batman fare. If you expect a commentary on current politics, you'll get that too. If you want to see an interesting thriller, that's present as well. And if you're one of those who thinks the movie is blatantly promoting terrorism? Well, I couldn't say you were wrong (though I would say you've missed the point). But the strength of the movie lies in its openness, to facilitate discussion and remember the importance of individual strength.