Whether the United States is the global equivalent of a justified policeman, a sanctimonious criminal, or a muddled combination of the two is personally explored in the narrative of The Departed through the lives of two Massachusetts State Policemen, one of whom is posing as a criminal (Leonardo DiCaprio) while the other (Matt Damon) is quite genuinely integrated into mob boss, Frank Costello's (Jack Nicholson) crime syndicate. In Scorsese's opening sequence, Costello, bestowing advice unto a young Colin Sullivan, declares, “When I was your age they used to say you could become cops or criminals. What I'm saying to you is this...When you're facing a loaded gun, what's the difference?” In terms of war, Costello's “what's the difference?” simultaneously validates and condemns America's self-superior and noble interference in the political schemas of foreign countries by casting the nation as the amalgamation of gallant and morally negotiable intentions.

Besides parallels between the sentiments of the American public and the thematic preoccupations of the film, The Departed makes direct references to the prevailing paranoia about terrorism today and to the current and possible political agendas of the future United States. In Captain Queenan's (Martin Sheen) speech of narrative exposition to William Costigan (DiCaprio) early on, Queenan announces “We (The United States) will probably be at war with the Chinese in twenty-odd years and Costello is selling a military technology.” Special significance should be attributed to the fact that it is this particular crime, the obtaining and bartering of United States military technology, for which Costello is most vilified. The initial stakeout and sting operation performed by the Special Investigation Unit (to which the corrupt Sullivan gets promoted) is not concerned with the murders that Scorsese allows the audience to see Costello commit or the drugs being peddled by his number one, Mr. French (Ray Winstone).

Instead the focus centers on Costello's apparent betrayal of American, terrorist paranoia, namely his selling of military microprocessors. Even though the sting operation fails and Costello and his Chinese buyers appear to have made their transaction without a hitch, Scorsese directs The Departed to satisfy American patriotism by revealing that not even Costello, in his unadulterated wickedness could deliver military secrets into the hands of a foreign government. By arranging for Costello to double-cross his Chinese buyers, Scorsese serves two purposes; He maintains Costello's villainous persona while concurrently preserving America's safety from retribution, deserved or not, from a foreign threat.

Costello's importance to the narrative as a villain cannot be overstated, considering the values for which he stands, and considering that he is the antithesis of the “Serve and Protect” SIU that he has infiltrated. The Irish mob boss begins the film in voice over with his perverse interpretation of the “American Dream.” Over newsreel footage of the race riots in Boston “some years ago,” Frank Costello declares, “I don't want to be a product of my environment. I want my environment to be a product of me…Twenty years after an Irishman couldn't get a fucking job, we had the presidency…No one gives it to you. You have to take it.” In the very next scene, Scorsese shows Costello in his neighborhood “shaking down” a local grocery store clerk, essentially taking “it.”

From that moment on, Costello's role in the narrative is to force his reading of the American Dream upon as many people as possible and it becomes up to those people to discover their identity within Costello's greedy interpretation. Costello alternately advises Sullivan and Costigan in his way of thinking, passing along such mantras and insights as “A man has to make his own way,” and “I haven't needed the money since I took Archie's milk money in third grade. And to tell you the truth I don't need pussy anymore either…But I like it.” Sullivan and Costigan, the respective recipients of this skewed advice, represent opposing values while sharing similar identities.

Sullivan, Costello's deceitful, conniving, SIU mole operates toward personal ends and embodies the ardent pursuer of personal wealth who characteristically views America's policing of the world as a right by a survival of the fittest attitude. Costigan, the equally deceitful, conflicted “rat” in Costello's crew sacrifices personal time and ambition in order to serve the commonwealth, channeling the modern counterculture, which objects to the United States occupation of Iraq as well as the American government's self-appointed duty to bring democracy to the rest of the world. Though strikingly similar, Sullivan's and Costigan's relevant deception of SIU and Frank Costello differ most decidedly in whom each deceives and whom each believes he is deceiving.

William Costigan initially believes he is misleading no one. As a cadet at the Police Academy, Costigan (like Sullivan) genuinely performs well enough to be assigned to SIU's Undercover Department. In his first council with Captain Queenan and Staff Sergeant Dignam (Mark Wahlberg), Dignam ridicules Costigan's tragic lineage and speculates as to why he joined the state police. Immediately afterwards Queenan alleges about his department, “We deal in deception here. What we do not deal with is self-deception.” The “here” that the captain refers to is of course SIU, which acts as the upholder of, even if not the participator in [as evidenced by Dignam and Captain Ellerby (Alec Baldwin)], the moral standard of America and consequently the ethical voice of The Departed. With that ethical voice, Queenan condemns self-deception. Costigan generally heeds Captain Queenan's warning and identifies for much of the film with neither cop nor criminal.

After a year of undercover work, his behavioral deception takes its toll on him and Costigan, in a heated exchange with Dignam proclaims, “I can't be someone else every fucking day.” The statement supports Costigan's avoidance of the perilous self-deception, yet once Costigan is officially retired from having to deceive Costello and his crew as well as everyone outside of Queenan and Dignam, Costigan betrays Queenan's warning. After steadfastly declaring to Sullivan in their first meeting late in the film, “Being a cop's not an identity. I want my identity back,” Costigan attempts to arrest Sullivan, contradicting what he knows to not be his identity. Reassuming the cop role after Queenan's warning and his own declaration, Costigan is not permitted to survive The Departed.

Sullivan too, must deceive everyone, even Costello, the man he had been most loyal to since the film's first sequence. He deceives his unit, his employers, his father figure, Costigan, and his fiancé, but like Costigan, Sullivan's most menacing moments of deception occur when he allows is personal ambitions to deceive himself. Sullivan often looks to the State Senate on Beacon Hill in the film, minimally but effectively expressing his desire to become an ever-important authority figure in an institution that ideally exists to uphold the moral fiber of American values. The problem with this of course is that Sullivan is morally negotiable and not ideally dependable in his ethical ideology.

Sullivan seems always trying to convince himself that he can attain this status even through his whole-hearted acceptance of Costello's perversion of the American Dream. The ultimate deception of himself comes after Costigan's murder, when Sullivan attempts to assume the power to judge the moral integrity of another, by recommending Costigan for the Medal of Merit. Two scenes later, Dignam, the last man remaining from SIU (besides Captain Ellerby) executes Sullivan in the same way that Costigan was killed.

Scorsese's denunciation of the perverse interpretation of the American Dream as well as the importance of defining oneself within it, is well supported through the narrative events of The Departed. Scorsese interestingly pardons neither Sullivan nor Costigan for his transgressions of duality. However, the ultimate triumph is still enjoyed by the morally upstanding who aspire to punish the wicked.

The downside was a few loose ends, like wondering how Sarah played by Geena Davis, possessed the power to let the sandworm in, to swallow Beetlejuice when the ghosts were weaker than the worm. Another loose end was how the dead couple got siphoned back to the world of lost souls, although one could figure that something was needed to inform the couple that a mortal had stolen the “Book of the Deceased”.

The imaginative loopholes where the actors like Alec Baldwin and Geena Davis went in an out of the after world, added to the momentum and tension of the film. One suspected that the deceased couple would try to make an attempt to get the new owners out of the house but there had to be complications like the hazard of reverting to the help of Beetlejuice or the additional plague on the already deceased couple because of a meddlesome Otho.

An early performance by Winona Ryder crowned the film. She played a convincing gothic suicidal teenager with a special ability to communicate with the dead couple and acted also to inform her parents that the ghosts were unwilling to be used for show. She interacts with Beetle juice in order to have him remove a ghastly curse on the ghosts but had to sacrifice her celibacy to marry him.

The wedding is comical in the way it is dragged out and ended before it is sealed and so is the combination of special effects and comedy with scenes such as one of he final ones where Beetle Juice has his head shrunk because he switched numbers for some other freak waiting dogs ages to get into the after world.