It is part of the quote " And happiness is thought to depend on leisure for we are busy that we may have leisure, and make war that we may live in peace." " WE MAKE WAR THAT WE MAY LIVE IN PEACE" - Aristotle S.S.D.D.: If using noclip console command, it is possible to see that one of Rangers that is sitting near several M16A4's at the start of the level has dog tags.No Russian: In the mission there are two cases which appears to be Modern Warfare 2 on the front and Modern Warfare on the back, it can be spotted on the back of the case as the player walks up the escalators or stairs to a store on the left.A message spelling out "THE DRWANTSTHEULTIMATEPOWERBASTARD" can be found within the four characters' biographies.Der Riese: Various easter eggs: This map contains a lot of different hidden surprises, including radio messages, the hidden song Beauty of Annihilation, and a game of hide and seek which unlocks an achievement.Shi No Numa: Various easter eggs: a hidden song called The One and radio messages.Verrückt: Lullaby for a Dead Man (hidden song): Plays after flushing a toilet three times.
Operation Little Saturn: Giant Red Apple.Underground Passage: Ghostly room, Kaiser Bear, Sticky Bear, German dance party.