Chief: My orders say I'm not supposed to know where I'm taking this boat, so I don't. But one look at you, and I know it's gonna be hot, wherever it is.
Willard: We're going upriver about 75 klicks above the Do Lung bridge.
Chief: That's Cambodia, Captain.
Willard: That's classified.
Chief finds out for the first time where they are headed and he's not happy to hear it.