What a complex film, lending itself to any number of readings. Today I present: lame, read it like the WOT and America's post 9/11 security strategy!!! (And of course, spoilers. But who hasn't seen this?)
The Joker is explicitly referred to as a terrorist throughout the film. I'm gonna go ahead and not pull a "mega depth hermeneutic", and agree with that one. We'll go ahead and slot Harvey Dent in as American idealism/Truth, Justice, and the American Way/all the good stuff the Founders stood for. Lt. Gordon, the mayor, associated judges and beauracrats all seem to be part of the state apparatus that stands as the material instantiation of the ideals Dent stands for: which is to say, a compromised version. You can't properly call Batman a state apparatus (although he works closely with the police) because he exists by virtue of his separation from the official enforcers of law and order.
When the film opens, the criminals are, by and large, on the run. Dent, Batman, and Gordon's cops are slowly but surely closing a net on the Gotham criminal's monetary fund. The civic spirit is so alive ordinary citizens feel empowered to dress up like Batman and go after criminals. Two blots remain- corruption within the police department that allows the mobster to be tipped off when the police are about to move, and the Joker, who early in the film seems more interested in terrorizing/robbing the mob.
The film makes the argument that without the Joker, criminals in Gotham would eventually be put "in the cooler" by the combined forces of Dent, Gordon, and "the Batman". Dent's refusal to cower in the face of threats of physical coercion (he stands up to the crook who pulls a gun on him), Gordon's good old American gumption, and Batman's combination of swift power and high technology all give rise to scenes of worried mobsters gathered to seek council. The Chinese businessman who temporarily saves their money from impoundment is still extradited via Bat-chute, and we are led to believe that he will squeal. Because Batman and Dent seem above corruption (both are avatars of justice), the film's running time would be very short if the Joker did not appear.
"Whatever doesn't kill you makes you stranger" and "Why so serious?" are the most haunting early verbal markers of the Joker's true nature. Throughout the Joker tells a series of different "origin stories" about his bizarre face. The effect is decidedly postmodern, making attempts to read a traditional set of character motivations onto him difficult. There are, I think, two clear explanations for the rise of Islamic fundamentalism and the attacks of September 11th which circulate popularly. You have the argument that wahhabism is the result of an ideological religion built on expansion that is committed to enforcing its big T truths by hook or by crook, and thus resentment against the West is the result of a disagreement and an ethical condemnation of a group of people refusing to live by the correct values, who must be appropriately converted or killed. The other explanation, popular among Ivan Eland and others, is that the form of violent Islamic fundamentalism seen among Osama bin Laden and others is the result of deep seated resentment generated by a combination of American military occupation of the Middle East, support for Israel, and the creeping effects of globalization in eroding culture.
Was the Joker cut by his father with a blade? Was his wife really frowning too much? The reader of the film that debates which of these stories is true is probably missing the point. Any one of these explanations could be true. What matters less is which is, and more what the Joker is actually doing, in the moment. The history of the doer is irrelevant- it is the deed itself that matters. The entire opening bank robbery scene is dedicated to enforcing this point. "The Joker" is constantly referred to as the planner, mastermind, and puppeteer of the entire operation. Yet the importance of the act is not what is says about the Joker, but that someone has refused to give into the fear and coercion offered by the mob. As a figure the Joker stands outside the interpellation offered by both the police (legal force does not deter him) and the mob (threats of violence motivate and excite him).
The Joker's history is besides the point. Wondering about or trying to explain his origins seems useless, even counterproductive. His acts, however, mark the points at which systems of logic/rationality seem to have exhausted themselves. The opening bank robbery succeeds because of the way in which the Joker ruthlessly plots the elimination of each of his fellow robbers; if violence governs, then we will have no honor among thieves. His murder of the Batman imposter points to the curiosity of the tolerance the system of law and order has for "the Batman": the Joker's act can be read as nothing more than another act of vigilante justice against a law breaker, no more illegitimate as Batman's, one which takes seriously the proclamation of identity. Because these Batman imposters have been given strength through the visible campaign of Batman and the police to clean up Gotham, their murder at the hands of the Joker is in some sense their "just dessert" for embracing a figure who simultaneously advances law and order while working outside of it.
Throughout the film the Joker is always one step ahead with his plots, evidencing a powerful sense of sophistication and knowledge. He knows to lie about the positions of Dawes and Dent when they are kidnapped so Batman will save the wrong one. He plots to get himself captured, setting up escape mechanisms well in advance. He knows enough about police tactics that he sets up the trap with the hostages in the uncompleted Trump Tower. He knows that citizens will be able to escape from Gotham only by boat, so he rigs them up with his "rational choice paradigm" trap. The Joker, is , frankly, too powerful to be any "real" figure. Thus the image of terrorism authored by the film is one of an all powerful, nearly omnipotent, and always already everywhere disturbance. Terrorism is always one step ahead. And powerful enough to kill Dawes, corrupt Dent, and drive the Batman to violate his own codes against violence and rights violations.
Nowhere is all of this evidenced more clearly in the conversation in the hospital between the Joker and Dent (now Two-Face). The Joker is able to pervert Dent's sense of goodness and justice so that he becomes a figure of vengeance, motivated by delivering punishment outside the confines of the law. As mobsters and corrupt cops are killed, we see the flipside of truth, justice, and the American way: the overarching sense of good and right that underlies the spirit of justice can ultimately corrupt its enforcement. One reason why this troubles me is because the film does not do a good job of portraying the victims of this violence compassionately. Essentially, they are all bad people who get what they deserve, except for Officer Ramirez, who was pressured into corruption to pay her mother's hospital bills. She is spared. External circumstances may influence justice. That is why Dent does not kill her after his coin saves her, but he does still kill the mobster when the coin bails him out.
Thus the necessity for Batman and Gordon to cover up Dent's violent crimes. It is evidence that the ideal of justice is purely ideal, not material. Even Dent was corruptible. So he must exist as a martyr in the eyes of the public ("we should all strive to be as noble as Dent"), even as the material reality of his existence contravenes the possibility of the ideal existing ("even Dent was not above it"). The victory at the end of the film is not in redeeming justice- it is in preserving it as a fiction to be consumed by the people of Gotham so that they may go on living their lives with hope. Necessary, perhaps, but also enabled through a governmental cover up which fingers Batman as the killer, turning him into an enemy of the establishment. Essentially: "the real enemy is the ideal of justice and stability, which gave birth to the Joker as its necessary correspondent. But because we cannot face up to the fact that it is these ideals which are the problem, lets just blame this law breaking guy in a costume who just HAPPENS to follow the spirit of the law, if not the letter". We cannot have justice with a figure committing injustice to make the concept sensible. I would do a Foucault riff here, but I think the shorthand does the trick.
And Batman himself is only able to capture the Joker by generating a "state of exception". Early in the film, at a dinner scene between Bruce Wayne and Harvey Dent, Dent argues for the old temporary suspension of civic rule, in which all powers are given to a sovereign to protect the people. Dawes points out that this was an epic fail (Caeser). Yet later in the film this very logic is perserved and endorsed. After building his massive NSA style surveillance operation, Wayne convinces Lucious Fox to use it just this once to track down the Joker. If they had not used the NSA apparatus, the Joker would have eventually killed the people on the boats (making irrelevant their humanity empowering decisions not to kill), and the SWAT teams would have killed the hostages dressed as crooks, creating a massive publicity crisis for the state apparatus embodied in the police. Instead the NSA device allows all of this to be averted. And the film encourages the viewer to support the fiction that such devices are "only used once". Conveniently, Batman's self-destructs. However, the security architecture enacted in the wake of 9/11 cannot simply be wished away or destroyed. In fact, its entire existence is premised on the idea that it only exists in one moment. Yet this one moment is constituted as a perpetual state of insecurity and unrest, meaning the state of exception is perpetuated. The film says "Don't sweat it, they really only use this stuff if they really have to", but the message of the rest of the film, owing to the Joker's omnipotence and Dent's corruptibility is "They always really have to!!".
Now one might say: but that tower and the hostages were only distraction from the real threat to Law and Order, the very public murders committed by Dent (including the possibility of his murder of Gordon's family). However the hostage crisis was a direct result of poor crisis management by the authorities, so the deaths of the hostages would have also been a devastating event.
Oddly, I think the film sort of makes a rather pragmatic conclusion about terrorism and security. These threats exist, but as a result of the systemic way in which systems of truth and rationality manufacture necessary disorders in their attempts to completely create order, and that the only way to handle them is through effective and canny use of a combination of repressive state apparati and mythology, in the form of Dent. Perhaps the film is just saying "this is how we must do this", but that in and of itself is still normative, and has the effect of closing off possibilities of thinking and doing otherwise.