This quote is in a 1979 film that revolves around a man named Captain Benjamin L. Willard (Martin Sheen) on a secret mission to assassinate Colonel Walter E. Kurtz (Marlon Brando), a renegade who's presumed insane. The title of this film is: Apocalypse Now. It is a 1979 American epic war film directed, produced and co-written by Francis Ford Coppola and co-written by John Milius with narration by Michael Herr.

With the plot of this film is about the Vietnam War in 1969. Army Special Forces Colonel Walter E. Kurtz has become insane; and, he now commands his own Montagnard troops, inside neutral Cambodia. He is actually behaving as a demi-god. Two officers, Colonel Lucas and General Corman, increasingly concerned with Kurtz's vigilante operations, assign Army Captain and Studies and Observations Group veteran Benjamin L. Willard to terminate Kurtz with extreme prejudice.

At its release, Apocalypse Now received universal acclaim. It was honored with the Palme d'Or at Cannes and nominated for the Academy Award for Best Picture and the Golden Globe Award for Best Motion Picture – Drama. Today, it is considered to be one of the greatest films ever made. This consideration is held by the National Film Registry in the U.S. Library of Congress.

More Info: en.wikipedia.org