The Departed

For those that are familiar with The Departed there's a couple issues that could be looked into more thoroughly. For instance, does the corrupt nature of state police forces relate to any type of American Terrorism? In a more detailed thought about it, does America secretly train troops such as Billy Costigan (Leo DiCaprio) or Colin Sullivan (Matt Damon) for illegal affairs such as stealing, killing, or international terrorism?
There is a lot of talk about terrorism that is inflicted on the United States, but there's never talk about the United States terrorizing other nations. The Departed takes a deeper look at the corrupt forces that we as a nation may be involved in. The life of Billy Costigan in The Departed is a complete lie. Basically his role is to be a spy and to take a look at deeper affairs that Massachusetts State Police uses while trying to hunt drug lords.
Like the sadistic role that mothers play in movies such as scream, I would argue that the corrupt nature of police takes a hint into illegal affairs that the US may get into. Of course we have spies, and of course we have corrupt officials, but I think there might be a relation with US illegal activities through movies such as The Departed paralleled to the hidden meaning of mothers and horror films.
When we see thriller movies such as The Departed and take a look at what US forces can do to "spy" I certainly believe that it parallels some sort of US international terrorism. Does the US take the lives of lost individuals and train them to perform secret operations that would be unmoral for the government to approve? I think the answer is yes, and that connections can be made through films like The Departed.